1The area usually referred to as Caesar’s Forum (Forum Iulium) (Fig. 1) and the later Imperial Fora (Fig. 2) cover an extensive area of what once was and to this day still is central Rome . Together with the Roman Forum and the Palatine Hill , this area constituted the absolute centre of Rome in the Republican and Imperial periods – a focal area for politics, trade and religion in Rome, and an area about which much has been written in classical archaeology. However, it is not that long time ago that archaeological research first began to be conducted in the area. When archaeological research in the area was initiated, it was driven by motives different from the ones in place today, and therefore the nature of the excavations undertaken during the time of Mussolini was of an entirely different nature from those of later periods. One historical period which has suffered immensely since the first excavations were undertaken is the time immediately preceding the archaeological excavations. In this period, the area was taken up by domestic housing blocks, namely the domestic quarter referred to as the Alessandrino Quarter. While this neighbourhood is attested through aerial photographs and written sources, not much is known about the material culture of it, since it was demolished and no documentation was undertaken of the quarter immediately before the destruction took place. One of the foci of the new Danish-Italian excavations[1] is to give attention to this phase in order to situate the Alessandrino Quarter within the overall archaeological and historical context of Rome’s post-Renaissance development. Furthermore, the project investigates to what extent ancient remains also found their way into the building history of this neighbourhood, which in turn gives insight into the amount of available ancient materials at the time of the construction of the Alessandrino Quarter in the 16th cent.[2].

2From the area that would later be covered by Caesar’s Forum, the earliest traces of human activity consist of sporadic finds of pottery together with levelling works, postholes, and a series of wheel-tracks, datable to between the 13th and 11th cent. B.C.[3]. During the 13th cent. B.C., parts of the geological substratum were levelled and terraced. A small section of archaeological stratigraphy connected to the levelled area contained impasto fragments datable to the Recent Bronze Age[4]. The before-mentioned wheel-tracks as well as postholes, probably belonging to a hut structure, were found to have been partly destroyed by three cremation graves datable to the 11th–10th cent. B.C., providing a terminus ante quem in the 12th cent. B.C. for wheel-tracks and postholes[5]. The three cremation graves belong to a group of ten tombs dated to the 11th and 10th cent. B.C.[6]. The tombs are understood to be part of a larger necropolis area located in the valley between the Capitoline and Quirinal hills , as indicated by additional finds of contemporary burials in the area of Augustus’ Forum [7]. During the 8th and 9th cent. B.C., the settlement pattern of Rome developed from small villages into larger centres of up to 200 ha[8]. In this process, the cemetery moved from the low Forum area to the higher Esquiline Hill , thereby liberating the lower valley areas for domestic and production purposes[9]. Notwithstanding this, two tombs dating to the mid-8th and last half of the 8th cent. B.C. have come to light in the Caesar’s Forum area[10]. Both graves belonged to infants and contained rich sets of funerary goods. The burials were situated inside a hut structure and provide examples of the well-known Latial practice of suggrundaria [11]. From the beginning of the 9th cent. and throughout the 8th and 7th cent. B.C., the area was gradually levelled with soil, as huts were constructed throughout the area[12]. Although the actual structures are largely obliterated, the use of the area is attested through the finds of a well, pits with archaeological material, and parts of a kiln[13]. This evidence together indicates that the area had acquired an organised domestic and production-oriented function at this point in time. In the south-eastern area of Caesar’s Forum, the remains of two Archaic houses, related wells and a street were excavated during the 2005–2008 excavations on the site[14]. The houses were constructed in the 6th cent. B.C. and underwent several architectural transformations until their destruction in relation to a fire sometime in the early 4th cent. B.C.[15]. The fire was followed by a period of rebuilding during the 4th and 3rd cent. B.C., and the area continued to be inhabited up until the first construction works of Caesar’s Forum commenced in 54 B.C.[16]. In the period immediately prior to the construction of Caesar’s Forum, the area was occupied by Republican-period elite houses.

3The erection of Caesar’s Forum was a project of extreme prestige: the first Forum of its kind to be realised in central Rome, located in a position of political and historical significance right next to the Roman Forum, the public space of the Roman people. In this respect, Caesar’s act of turning an area used for the private domestic sphere of the elite into a public domain only contributed to the grandeur of the enterprise[17]. Today, two-thirds of Caesar’s Forum have been uncovered. The major parts were unearthed in the excavation campaigns of 1930–1932 and 1998–2008; the latter being conducted on the occasion of the Great Jubilee, as part of a joint project between the Ministry of Cultural Heritage, the Sovrintendenza Speciale per i Beni Archeologici di Roma, and the Sovrintendenza ai Beni Culturali del Comune di Roma. Between 1998 and 2000, the excavations unearthed an area of 3500 m2 in the southern half of Caesar’s Forum[18]. Before the construction of Caesar’s Forum could begin in the 50s B.C., two major demolition tasks needed to be conducted. Firstly, the Republican houses were demolished, but, in addition to this, the area needed to be entirely levelled. While Cicero and Oppius had bought the land on behalf of Caesar in 56 B.C. from private owners of the Roman upper class[19], the construction of Caesar’s Forum only began in 54 B.C. with a grand-scale levelling of the area, which was otherwise sloping from the Capitoline Hill as well as the Quirinal Hill[20]. By evening out a height difference of 3–4 m over 50 m in the northern end of the area, a relatively level forum square was created at a height between 14 and 15 MSL. The levelling operation effectively demolished all remains of previous phases in the area towards both the Capitoline and Quirinal hills, while large parts of the south-eastern forum area were spared. In fact, excavations here have revealed important stratigraphic sequences dating between the Early Iron Age and the Republican period[21]. Likewise ascribable to preparatory activities undertaken prior to the construction of the Forum was the removal of grave contents from graves exposed during the levelling of the area. In terms of dimensions and shape, the burials corresponded to the before-mentioned intact Iron Age graves that had been found nearby in the 1998–2008 excavations[22]. The emptied graves were found to be filled with coarse-grained sand similar to what has been recorded underneath the tufa-stone blocks covering the forum square, indicating contemporaneity between the emptying of the graves and the preparations for the construction of the forum[23].

4The latest fill of a well located in connection with a Republican house labelled ›edificio 1‹ is contemporary with the construction of Caesar’s Forum and mirrors the demolition of private houses through the finds of tiles and painted wall plaster. The well was sealed off by the superimposed tufa-stone pavement on the forum square. Large quantities of pottery were excavated from the well both in the shape of complete and fragmented vessels. The material composition indicates that the material was deposited within a limited time span, potentially in relation to the cleaning of the area or on the occasion of the house demolitions. As indicated, the latter option might well be reflected directly through the finds of tiles and wall-plaster fragments[24]. However, it seems reasonable to consider a ritual significance in the deposition of the material. The find of a sea-shell at the bottom of the material deposition might in fact point towards such an interpretation[25].

5The Caesar’s Forum complex became a benchmark for the later displays of Roman imperial power encountered in the Imperial Fora in later centuries, such as seen in Augustus’ Forum, Nerva’s Forum and Trajan’s Forum as well as in the Templum Pacis complex initiated by the emperor Vespasian[26]. In one end of the rectangular square (approx. 115 m × 30 m) of the complex, which was otherwise surrounded by colonnades on the remaining three sides, was the temple to Venus Genetrix, the mythical ancestress of the gens Julia[27]. However, Caesar did not live to see the Forum Iulium finished. Although Caesar inaugurated the temple in 46 B.C., the complex was not completed before but only after his murder in 44 B.C. Its construction was finalized much later by Octavian, Caesar’s adoptive son, who also enlarged the forum square’s original layout towards the south[28].

6By the end of Late Antiquity, Caesar’s Forum fell out of use as an open space, and its structures were gradually dismantled and demolished. The entire area covered by the Imperial Fora was subjected to an intense spoliation process, and building materials were reused in new structures. Already by the middle of the 9th cent. A.D., what was once the open square of Caesar’s Forum became occupied by orchards, vineyards, and vegetable gardens. Aside from these, the medieval occupation at the site consisted of one-storey single-room houses, the so-called domus terrinee (Fig. 3). As is still visible today from the unearthed remains on the site, the domus terrinee often incorporated ancient architectural elements from the surrounding areas, such as marble blocks and fragments[29]. The post-Late Antique phases further saw the construction of the churches of Sant’Adriano al Foro (established in what former had been the Curia Iulia ) in 630 A.D. and Santi Luca e Martina in 625 A.D. Bordering the Caesar’s Forum area, the façades of both churches faced the Roman Forum. Probably during the 9th cent. A.D., a construction was raised covering the interior of the so-called Basilica Argentaria as well as the area behind the temple of Venus Genetrix. This building held both formal representational rooms as well as smaller rooms and storage spaces. The general layout of the building suggests that it might have been used as a place of accommodation and assistance for the numerous pilgrims reaching Rome, and it should possibly be identified as the diaconia of Sant’Adriano[30]. In connection with the construction of Via dell’Impero and the associated excavations within the Imperial Fora area in the 1930s, the church of Sant’Adriano al Foro was deconsecrated, all elements dating to the periods after Diocletian’s time removed, and the building brought back to its ancient form. Towards the 11th cent. A.D., the medieval borough at Caesar’s Forum was abandoned, and the area became part of a swamp, colloquially called ›I Pantani‹[31], which existed until the establishment of the Alessandrino Quarter in the 16th cent.

7The most recent historical phase at the site of Caesar’s Forum is constituted by the remains of the Alessandrino neighbourhood. Its construction was undertaken in the 1570s, and it existed until the 1930s; that is, a period of more than three centuries of Rome’s urban history. At the time of its construction, Rome underwent a rapid population growth that prompted the need for new residential areas – in this regard, the city’s historical centre, once the area of the Imperial Fora, was an obvious choice. Already at the beginning of the 16th cent., the attention of the papal government was drawn to opening extensive building projects in essentially uninhabited areas beyond the historic city centre to the west and south in the Trastevere, as well as in the Trevi and Monti areas. This caused a fundamental and much-needed transformation of the extent of the urban nature of Rome[32]. In this regard, the above-mentioned swamp area, ›I Pantani‹, was drained, and the new residential area arose in the later part of the 16th cent. One of the major promoters of this grand urbanisation project was Cardinal Michele Bonelli (1541–1598), who went by the name Cardinal Alessandrino, together with the Della Valle family, who were the owners of the Caesar’s Forum area. The new residential quarter was named after the first mentioned, as was one of the neighbourhood’s main streets, the Via Alessandrina. The draining and land retrieval were realised by Comune di Roma between 1582 and 1584. The work consisted in depositing a uniform layer of soil on the existing gardens, thereby creating a new and elevated dry surface. At the same time, the Cloaca Maxima was restored in order to prevent reoccurring water floods. In 1584, the Della Valle family obtained authorisation to open new roads, which led to the establishment of the streets Via Alessandrina, Via della Salara Vecchia, Via Cremona and Via Bonella. On the Della Valle family’s land holdings, 35 houses were erected by 1590[33].

8Over time, the neighbourhood underwent renovations, elevations and expansions. The first demolition of houses in the Alessandrino neighbourhood was undertaken in the late 1800s, caused by the unification of Via Cavour and Piazza Venezia. In the 1930s, new plans for the area were put in place. At first, the idea was to elongate Via Cremona towards the Colosseum, but this proposal was modified and extended, and a rectilinear street from Piazza Venezia to Colosseum was constructed: the Via dell’Impero, today’s Via dei Fori Imperiali. The construction of the triumphal road led to the final and all-encompassing demolition of the Alessandrino Quarter. In about one and a half years, the entire residential area together with its five churches was erased, the last houses being pulled down in 1933[34]. About 1000 families were evicted and transferred to newly built neighbourhoods in the outskirts of Rome, while the Via dell’Impero was inaugurated by Mussolini on 28 October 1932[35] (Fig. 4).

9The excavation area is situated in what was once the most southern part of the Alessandrino Quarter and corresponds to an urban sector between the now-defunct Via Bonella and Via Cremona. Based on the records of the land registry Pio Gregoriano and the Brogliardo (Fig. 5. 6), datable between 1820 and 1824, data pertaining to this area have been acquired, including the cadastral data of the property, the presence of buildings, the number of storeys and the owners. The excavation thus concerns a portion of plot 1635, corresponding to numbers 43 and 45 of Via Bonella. The remains of the ground floor and cellars of the houses, according to the Brogliardi, belonged to a Giovanni Fioravanti.

10The two-storey building was equipped with two entrances, most likely corresponding to two residential units, as evidenced by the presence of house numbers assigned to the same owner: numbers 41, 43 and 45 on Via Cremona and number 56 on Via Bonella[36].

11Photographic material from the ›Pianta fototopografica della Zona Archeologica di Roma‹ provides additional insights into the last habitational phases of the area currently under excavation[37]. The superposition of a recent satellite image has permitted the determination of the precise position of the excavation area in relation to the structures of the Alessandrino Quarter prior to the demolitions (Fig. 7. 8). An oblique aerial photo (Fig. 9) shows, from the north-west, the Alessandrino Quarter in its entirety until the Piazza Venezia with Via Cremona and the area currently under excavation visible, although at a distance, opposite the church of Santi Luca and Martina. A similar situation is perceived from another angle in Fig. 10 [38]. Aside from giving insights into the actual appearance of the neighbourhood, the archival photographs further present information of potential relevance to the last construction phase, as for example Fig. 11, which shows an aerial photo and a photo of Via Cremona most likely taken from the ›Altare della Patria‹. In the bottom left corner, parts of a three-storey building can be observed, hereby presenting an additional floor compared to the number obtained from the land registry of 1820–1824.

12The first phase of the new excavations took place between 14 December 2018 and 6 March 2019[39]. Additional field documentation was conducted in April and May 2019. The excavation was coordinated by Massimo Vitti and supervised by Giovanni Murro in collaboration with Cominio srl. (Fig. 12) under the direction of Jan Kindberg Jacobsen, Claudio Parisi Presicce and Rubina Raja. Contemporary with the excavations, a sub-project was launched during winter 2020 in which a 3-D scan of Caesar’s Forum was undertaken. Furthermore, a topographical map was created, which is aligned with the map covering the rest of the Imperial Fora area. The 3-D scans were produced through the use of drones. The two 3-D models were produced in CAD in 1 : 50: one is showing the present-day street level and the other the original late Republican-period forum level. Into these models, previously collected digital and analogue excavation and topographical data from the Archivio dell’Ufficio dei Fori Imperiali are also being incorporated.

13The excavations, which were conducted in the area immediately to the north of the domus terrinee of the Forum, witnessed the removal of the superficial levels of the urban gardens in the area and brought to light the demolished remains of houses belonging to the most southern part of the Alessandrino Quarter, corresponding to a domestic sector between the now lost Via Bonella and Via Cremona. The residential complexes presented here were entirely destroyed during the construction of Via dell’Impero, which entailed the demolition of the neighbourhood. Specifically, the demolition of the housing block between Via dei Carbonari, Via Bonella, Via Alessandrina and Via Cremona, including the area currently under investigation, was initiated in the middle of September 1932[40] and finished during the course of that same year[41] (Fig. 13).

14The initial work involved the removal of two stumps of trees and proceeded with the gradual removal of the topmost layers of soil and contemporary rubble filling. The excavated area forms a six-sided concave polygon in an L-shape (12.20 × 8.20 × 6.20 × 10.80 × 6.50 × 20.10 m). This irregular shape was necessitated by the presence of three holm oak trees (Quercus ilex) growing near three corners of the site. In a coming phase of the project, it will most likely prove necessary to cut down and remove these[42], as they stand in locations of scientific relevance. Two specimens are located at opposite ends of the long side towards the Fori Imperiali and situated right above a part of the eastern portico of Caesar’s Forum. The third tree, which stands at the south-eastern corner of the excavation area, occupies a spot in the vicinity of which Archaic phases have already been attested in earlier excavations[43]. Consequently, it is expected that remains of roads and burials might be located underneath, and therefore this is one of the most important sectors related to the understanding of the most ancient phases of the site, which will provide crucial information about the earliest history of Rome and add significantly to our general archaeological knowledge (Fig. 14).

15In relation to the construction of Via dell’Impero, the later Via dei Fori Imperiali, green areas were established alongside the road. Upon the removal of the tree stumps in the excavation field, the effects of the root system from the trees planted at the time of Mussolini could be observed on the underlying levels, including the top of the walls beneath.

16The excavation activity at Caesar’s Forum initiated in March 2021 (and preceded by the mentioned campaign of preliminary investigations in 2018 and 2019) has focused on a limited section between Via Bonella and Via Cremona, corresponding not only to a section of the eastern portico of Caesar’s Forum but also to a part of the first habitation of the Alessandrino Quarter. Upon the removal of a compact layer of building debris from the general levelling of the area, carried out in connection with the construction of the Via dell’Impero and, specifically, the broad pedestrian walks and green areas along its western side, the excavation unearthed remains of walls from the ground floors of the habitational quarter. On a general note, the excavation revealed extremely scarce archaeological material, datable to the very latest phase of domestic life in the Alessandrino Quarter during the decades preceding the demolition 1931–1932. The houses were close to completely emptied except for the occasional finds of wine, medicine and ink bottles in glass, and rare occurrences of pottery fragments (Fig. 15. 16. 17). Emerging from this is the picture of a highly organised process of expropriation and subsequent rehousing of the inhabitants. A process in which the material remains – including debris – from the last inhabitants were carefully removed. However, the fortunate find of a closed and inaccessible drain context, US 1133, which will be discussed further below, provides us with some insight into daily life during the last days of the Alessandrino Quarter.

17In order to facilitate documentation, each room, both those on the ground floors and in the basements, was given a number (currently ranging from I to XXXI). Inside the rooms, the multiple building activities (i. e. extensions, re-functionalisations and demolitions) carried out during the last phases of the life of the structures were recorded. At the current state of the investigations, Rooms I–VII and XII–XIII are excluded from the excavations. Rooms VIII, IX, X, XVI, XVI and XVII (defined as Area 1 upon the removal of the most recent structures) are currently of more interest (Fig. 18). This is the case because they potentially preserve, below the structures of the 18th cent., an intact stratigraphy spanning from the 16th cent. and back to the most ancient phases. Given the presence of the cellars, the stratigraphy in the southern part of the excavation, constituted by Rooms XI, XV and XVIII, is less likely to be preserved. For this section, it is now possible to reveal a consistent building activity datable between the middle of the 19th cent. and the years immediately following the Unification of Italy. By comparing the height measurements of the floors to those of the medieval domus terrinee, it became clear that the floors of the cellars intrude on the medieval layers, probably cutting into the latter by around 10 cm.

18Situated in the northern part of the excavation area between Room II to the east, Room X to the south and Room XVII to the west.

19The extent is defined by wall USM 1042 to the north, USM 1037 to the east, USM 1046 to the south and USM 1018 and US 1044 to the west.

20Room of a sub-quadrangular shape, probably of habitational function (bedroom or living room). The southern part of the room was partially excavated in 2019 (Fig. 19). It was covered by the debris of US 1001. The room is characterised by floor paved with white and red hexagonal tiles with borders with the distinctive floral-patterned decoration (USR 1074). As with most of the preserved rooms, the floor of this particular unit also received a central hole, allowing for the filling of the subjacent spaces with rubble during the demolition of the Alessandrino Quarter[44]. In the case of this room, however, as with the adjacent Room X, which was located on top of what was originally an open courtyard, the excavation has verified the lack of basements and the presence of interesting stratigraphical units pertaining, for the upper layers, to fills of the modern period (US 1123 and US 1145). The sub-circular cut -1075 is filled with the rubble layer US 1001. The paving is interrupted in the south-west part by a wall of perforated bricks of sub-rectangular shape (USM 1078), pertaining to Room IX. The removal of the paving (USR 1074), together with observations of the sections of the cut -1075, has demonstrated the existence of an earlier paved floor (USR 1115). This floor is made of tightly packed pebbles tied with only very little mortar. Some marble fragments (primarily lunense) were found reused in the paving. The removal of USR 1115 further revealed the preparatory layer in pozzolana. At the bottom of this, a fragment of the imprint of another (earlier) paving of rectangular bricks (USR 1124) emerged. The paving is cut by US -1125 and filled to the north by US 1126 and to the south by US 1123. This last unit is a layer of silt containing archaeological material datable from the Roman period to the 19th cent. Notable is the presence of numerous Roman tesserae and fragments of revetment in different sorts of stones together with a high quantity of pottery fragments from the 17th cent. (Fig. 20. 21. 22). Stratum US 1123, and partly the USR 1124, cover part of a wall of uncertain function, constituted by blocks of tufa and pozzolanic mortar (USM 1127) and oriented north–south. The US 1112 also covers another wall in blocks of tufa tied together with pozzolanic mortar (USM 1128), oriented east–west and characterised by a perforation hole (probably a channel?). Both the walls USM 1127 and USM 1128 are connected to the same construction phase. In the north-west corner of the room, below USR 1079, there is a sandy and silty layer. Its origin can be connected to a duct in iron placed in this corner. The layer covers a channel (USM 1141, northern continuation of USM 1135) oriented east–west.

21The stratum US 1123 covers another level of sandy silt (US 1145) of reddish brown colour, also cut by -1125. The layer contains numerous residual fragments of the Roman period and should probably be understood as the result of a levelling and elevation of the area in the modern period. A quadrangular cut carried out in the north-western corner, between the walls USM 1037 and USM 1042, has permitted the final verification of the initial understanding of the layers. The stratigraphic hole has attested to the presence of four further levels (US 1149, US 1150, US 1151 and US 1152) below US 1145, and it has also established the entity and function of the cutting -1125 – a probable foundation trench for wall USM 1142, the depth of which overlaps with all the above-mentioned strata.

22Situated in the northern part of the excavation area, between Rooms VIII and X.

23Delimited to the north and east by USM 1078, to the south-west by USM 1018, to the south by the masonry spur USM 1048; subdivided by USM 1046 to the south. Delimited from Room X by the partition walls USM 1082 (to the east) and US 1081 (to the south).

24Room of irregular shape due to partial occupation by the extents of Rooms VIII and X; completely covered by the layer US 1001 of the demolitions (Fig. 23). Room VIII has an L-shape. The walls which divide the room from VIII are simple partition walls in perforated bricks (USM 1078). The wall cuts the USR 1074 (cementine-paved floor). The room is paved with hexagonal tiles (USR 1079), evidently shifted and of a different height compared to USR 1074. In the corner between USM 1048 and USM 1018 is a hole in the paving, which can be connected to a duct/channel in this location and to a drain (see Room VIII). Below USR 1079 is the sand-silty layer US 1133, which yielded much material. US 1133 was deposited in a channel (USM 1141) oriented east–west. The archaeological material obtained from this channel deposit provides one of the rare insights into the occupants’ daily life during the second half of the 19th and early 20th cent.[45]. The channel must have received material from various rooms with different functions in the building above. The presence of animal bones, bronze spoons and eating plates indicated that it might be a kitchen situation, whereas the finds of shirt buttons in glass and bone, and several coins might have resulted from laundering. The contexts were likewise rich on small medicine glass bottles (Fig. 24)[46].

25Below the channel, stratum US 1145 came to light, which extends all across Room VIII and is currently under excavation. Walls USM 1046 and USM 1048 bisect the room. The southern part of the room occupies a part of Room X; it has a pseudo-rectangular shape and opens towards Room X. It is delimited to the east by wall USM 1082 and to the south by USM 1801. Both USMs are constructed in perforated and yellow bricks. The paving (USR 1080) is of hexagonal cementine tiles in the entrance to Room X, while in the space between USM 1082 and USM 1081 it is in rectangles of red and white colour and with geometric decoration. In this zone, there is a circular perforation in the floor with an iron manhole cover and an opening for what must have been a toilet.

26This all rests on a pebble flooring (USR 1083), similar to USR 1115 brought to light in Room VIII and pertaining to the same construction phase (Fig. 25). The pebble flooring is also set in pozzolano and covers stratum US 1142. Below this, corresponding to the drain revealed in the USR 1080 paving, a quadrangular structure (USM 1046), which can be interpreted as a septic tank, was unearthed. The cover of the tank was constructed as a low brick vault with flat extrados in pozzolanic mortar. The cleaning of the faces of wall USM 1046 showed that this was characterised by a brick arch to protect the cover of the structure below (Fig. 26).

27The structure mentioned above appears to have been constructed on the ground; on its four sides, the masonry is constituted by small blocks of tufa (max. 10 cm), set in regular horizontal rows. On three sides (east, north and south) the middle parts of the walls are furnished with a rectangular hole (0.40 m × 0.10 m), the upper side of which is constituted by a brick placed horizontally. The fill of the structure is constituted by two layers (US 1146 and US 1147), both with relatively little material, mostly fragments of glass and a few fragments of glazed pottery of the modern period. US 1147 exhibits a strong organic component, verified both by clear chromatic and compositional components (dark grey colour, silty clay consistency and rich in carbon).

28The general characteristics of the structure seem to suggest an earlier date compared to the 19th- and 20th-cent. phases during which the structure was certainly in use. This is clear from the interventions, probably of later dates, such as the cover, and, significantly, from the drain from the small Room VIII and the quadrangular structure underneath.

29Situated in the central northern section of the excavation area, between Rooms VIII to the north, II to the east, XI to the south and XVI to the west.

30Delimited by walls USM 1046 to the north, USM 1037 to the east, USM 1035 to the south-west and USM 1071 to the south-east.

31Room of rectangular shape, oriented north-west–south-east, size 3.71 m × 5.36 m. The room was initially covered with a stratum of rubble (US 1001). Below this, a tightly packed pebble floor (USR 1083) was brought to light. Later structures are placed on the floor level, which probably belongs to an open space (courtyard?); to the north, placed against wall USM 1046 is part of the Room IX with the walls USM 1081 and USM 1082 and the floor USR 1080; to the north, resting on the floor are the structures of Room XII (a space perhaps dedicated to laundry activities), defined by wall USM 1035 and a floor plane of bricks with marble patches (USR 1084). Below floor USR 1083, stratum US 1142 was found. This is a modern fill like the underlying US 1145. The two levels are of comparable composition and feature many ceramic fragments from, among other periods, the Roman. The same stratum likewise revealed a notable quantity of 17th-cent. ceramics and sporadic finds of pottery datable to the 13th cent. (Fig. 27. 28). To the north, stratum US 1142 covers the vault of the septic tank denominated USM 1144 (= USM 1128) and to the south a covered structure (USM 1154) oriented east–west. The construction is constituted by a roof in cement and blocks of tufa and further characterised by the presence of recent fragments of plates as well as ancient fragments of amphorae. The removal of US 1142 allowed for further observations regarding the masonry of the structure USM 1154. The facing is constituted by blocks of tufa of small to medium dimension laid in pseudo-horizontal fashion. About 0.40 m from the top of the roof/cover, at two-thirds of the height of the north wall of the structure, the facing includes a larger number of reused, fragmented bricks, laid pseudo-horizontally with a slight inclination towards the west. This probably reflects a mending of the roof, probably connected with a later reworking of the structure. In the north-western corner of the structure, two blocks of peperino were reused in order to reinforce the corner. The masonry of the western side of the structure presents different characteristics: While reused bricks are frequently used in the central part of the external facing, blocks of tufa set in abundant grey mortar are more frequent in the upper part and probably form a part of the roof of the structure. After the removal of the mentioned roof/cover, it was easier to evaluate the masonry structures constituting the building as well as the silty sand fill (US 1173) (Fig. 29). The perimeter of the structure has a pseudo-rectangular shape (2.10 m × 1.40 m), and the northern and western walls are not perfectly orthogonally aligned. They meet USM 1037 to the east while they are cut by wall USM 1178 to the south. The masonry structure is constituted by a face of travertine blocks arranged in a quite chaotic manner. The upper part of the wall sees the presence of horizontally placed, rather large blocks of tufa. Below, the elements appear to be more arbitrarily arranged with the insertion of smaller stones as well as fragments of bricks. The excavation of the fill has produced a large quantity of pottery and glass fragments together with minor objects and a notable number of coins (16 bronze and 1 silver). Everything can be dated to the 16th cent. Conservation of the bronze coins is pending, but the silver coin is readable as a papal issue related to the papacy of Giulio III and can be precisely dated to the year 1555 (also the year of the pope’s death) (Fig. 30. 31. 32. 33).

32Situated in the southern part of the excavation, between Rooms XV to the east, XVIII to the west, XIII to the south and XVI to the north.

33Delimited by walls USM 1101 and USM 1102 to the south, USM 1035 to the north, USM 1010 to the west and USM 1086, USM 1097 and USM 1146 to the east.

34Room of rectangular shape (3.42 m × 4.74 m) oriented north-west–south-east, adjacent to Room XI, from which it is separated by walls USM 1086, USM 1097 and USM 1148. The room provides access to Room XVI to the north and Room XII to the south (not excavated).

35The room was covered by the rubble of stratum US 1001. This covered a floor level (USR 1103) in red rectangular bricks (14.7 cm × 30 cm) arranged in an alternating pattern. In this case too, the floor is disturbed by a wide cut (US -1104), which facilitated the filling of the cellars below. It was possible to verify how the floor was partially covered by wall USM 1148 along the eastern side. Originally, Rooms XV and XI were joined and shared the same floor levels for a period. USR 1085 of Room XI and USR 1103 of Room XV are in fact constructed with the same materials, arranged in similar fashions, and have the same elevation. The removal of floor USR 1103 has brought to light the vault of the room below and a partition wall oriented north-west–south-east (USM 1138), which again cover the extrados of the same vault/arch (USM 1139). The room unearthed is different from the other cellars. The internal walls are completely covered in white plaster, and on the eastern wall, iron brackets were inserted. These carried ceramic heaters, one of which was found in situ. On the same wall is a square iron plaque, illegible but seemingly advising caution.

36Situated in the southern part of the excavation, between Rooms V to the east, XII to the south, XV to the west and X to the north.

37Delimited by walls USM 1037 to the east, USM 1088 and USM 1087 to the south, and USM 1448 and USM 1086 to the west.

38The north–west-oriented room of rectangular shape is adjacent to Room X with which it shares walls USM 1071 and USM 1035. On this side as well as the south side, the room is furnished with two entrances which facilitate communication with Room X to the north and Room XXI to the south (not excavated) (Fig. 34).

39The room was covered with the rubble of US 1001. Below this, a brick floor was brought to light (USR 1085), of which each element measured 0.28 m × 0.25 m. The USR is cut by the hole -1090, which served to fill the subjacent cellars after the demolitions. The removal of the floor identified the presence of another floor layer in yellow bricks (USR 1130), arranged in an alternating, orthogonal pattern. In this case, the bricks measure 0.26 m × 0.14 m. To the east of the paving, below USR 1085, is a small channel, its bottom constructed of yellow bricks and its sides of tufa and fragments of bricks (USM 1121). The channel, which belongs to the same phase as USR 1130, is oriented north-west–south-east, as is wall USM 1037. The structure had a cover visible in the southern section of the room. It is preserved for a length of 4.77 m, and it is ca. 0.50 m wide and 0.20 m deep. The channel is slightly inclined towards the north. Also in this case, the structure is partially disturbed by the cut -1090. After the removal of the channel USM 1121 and the floor USR 1130, the underlying evidence was brought to light: These included the extrados of a vault (USM 1132). This construction constituted a part of a wide barrel vault which spans the Rooms XI and XV (USM 1139). The vaulted structure (USM 1132) in Room XI is constructed of blocks of tufa of small and medium dimensions as well as bricks set in very strong pozzolanic mortar. The vault is interrupted by a stairwell (USM 1122) constituted by a supporting structure in bricks and steps in peperino. The staircase belongs to the last phase of the building and most likely belongs to the same phase as the floor USR 1085. The steps of the stair rest on, and interfere with, the fill (USM 1175) of the wall below wall USM 1148 (USM 1174).

40Situated in the central area of the excavation, between Rooms XVII to the north, X to the east, XV to the south and XXII to the west.

41Delimited by walls USM 1018 to the north, USM 1034 to the east, USM 1035 to the south, and USM 1030 and USM 1033 to the west.

42Room of rectangular shape (5.90 m × 3.54 m) oriented north-west–south-east. The room was initially covered by the rubble layer US 1001. A part of the walls and the rubble fill of the room were disturbed by a cut, which served to accommodate the armed cement platform that carried the crane used in the excavations of 2000 (respectively -1008 and US 1016).

43The removal of the rubble revealed a portland cement floor, which belonged to a room of service function (USR 1020). The paving was perforated by a sub-quadrangular cut (1.84 m × 1.86 m), which also partially encroached on a part of the wall structure USM 1018. The room was connected with Room X to the east through an entrance (blocked in later phases) defined by a peperino threshold (USM 1021). Below the floor USR 120 a system of hydraulic structures were found. This was constituted by walls, basins and channels (USM 1157, USM 1158, USM 1160 and USM 1159), all related to disposal of water which was channeled into cisterns or septic tanks. The structure has been disturbed by cuts of uncertain function (-1162 and -1164). The gradual removal of USM 1018 highlighted a notable presence of residual material from the Roman period, some of which was already attested in the walls cleaned in 2019. The material thus reused mostly consists of bricks and fragments of amphorae, but it also includes marble elements. Worth mentioning is a composite capital perforated with holes for reuse – probably as a fountain (FC 5130) (Fig. 35) – and two column fragments (FC 5134 and 5135) (Fig. 36. 37). Upon the complete removal of the structures, US 1145 turned out to extend to this part of the excavation as well, a very interesting observation in so far as it represents one of the few stretches of stratigraphy preserved over a longer period of time, from the present until the most ancient periods.

44Situated in the northern part of the excavation area, between Room VIII to the east, Room XVI to the south, and the border of the excavation to the north, constituted by wall USM 1042.

45Delimited by walls USM 1042 to the north, USM 1044 to the east, USM 1018 to the south and USM 1029 to the west.

46Room of quadrangular shape, similar dimensions and function as Room VIII, and a size around 3.29 m × 4 m. This room was initially covered by the rubble stratum US 1001 too. Below this, a floor paved with red and white hexagonal cementine tiles was found (USR 1022). The floor plane was broken by a wide cut (US -1023), which also partially disturbed wall USM 1018. This was filled by a layer of rubble named US 1024, of the same composition and colour as US 1001. Below the floor, partly damaged by the mentioned cutting, a drain channel of brick (USM 1028) was found, already documented during the preliminary excavation of 2019. Similarly, a portion of wall of tufa blocks and bricks (USM 1029) running directly east of the mentioned drain came to light. Its construction technique and the slightly different orientation compared to the general trend of the walls suggest that the construction belongs to a phase which is later than the construction of the other walls. The USM 1029, oriented north-west–south-east, forms the continuation of wall USM 1043 to the north and USM 1030 to the south. The elevation visible to the east sees the presence of a sewage arch similar to that observed in the elevation north of wall USM 1042, sharing both constructional characteristics and height. The preparation layer of floor USR 1022 covers a stratum of sandy silt of brown colour, almost devoid of material (US 1134). In turn, this covers defunctionalised masonry structures. One of these is the channel USM 1136, a brick construction preserved for ca. 2.30 m and cut off in both the east and west ends (Fig. 38). The section of the channel is rectangular, its width measuring ca. 0.30 m. In all probability, the structure which abuts wall USM 1018 was connected to the hydraulic collection system to which USM 1157, USM 1158 and USM 1159 also belonged. The eastern part of the channel was furthermore certainly associated with USM 1144, interpreted as a septic tank, which was undoubtedly older but remained in use until the last phases of activity in the Alessandrino Quarter. To this, wall USM 1137 also abuts. It continues under USM 1044 and constitutes the ideal continuation towards the south-east, although it is not directly stratigraphically related to it. The wall is preserved for ca. 1.50 m and exhibits a more slender thickness (ca. 0.34 m) compared to the load-bearing walls of the plot (0.64 m in average). The US 1134 is in all respects comparable to US 1123 and covers stratum US 1145.

47Most of the excavated structures belong to the 19th-cent. phase of the history of the neighbourhood, characterised by a period of consistent modernisation, generally datable between the middle of the 19th cent. and the Unification of Italy.

48Furthermore, it was possible to observe, for the ground floors of the buildings, that, in this phase, partial re-functionalisations of some of the rooms were carried out. In some cases, this meant that common spaces/service quarters were upgraded to living rooms. A good example is constituted by Room VIII, the floor of which was initially constructed in rectangular bricks of which only the imprint survives (USR 1124). On top of this, a second floor consisting of river pebbles (USR 1115) was laid. The presence of the same floor type in the contingent Room X shows how they originally formed a single larger service area. The choice of a paved (selciato) floor, a type of floor which became widespread in urban areas during the course of the 18th cent. and replaced beaten floors, facilitated easy maintenance as well as transport of water. Accordingly, it is no coincidence that a large number of hydraulic structures should be found in these particular rooms. After the new cementine flooring was laid in Room VIII, which transformed the space into a living room, Room X preserved its attributes, maintaining the pebble floor and the structures connected to a constant use of water, such as USM 1084, and the room can therefore be interpreted as a probable laundry. Similarly, Room IX (between Rooms VIII and X) can be interpreted as a toilet. A further substantiation of the tie between the two rooms may be found in the presence/passage of water and the position of two quadrangular structures (USM 1044 and USM 1154), which can be identified as tanks for dispersal of waste, presumably of 18th-cent. date. Both rectangular constructions were parts of the original drainage system used until the last phases of the building. The central element of the hydraulic system of the complex was the masonry block constituted by USM 1018 (belonging to the early phase of the complex) and the later added basins USM 1157 and USM 1158, connected to a system of channels which directed the water into the tanks first mentioned.

49While it was possible to demonstrate an important stretch of 17th–18th-century stratigraphy preserved below the structures for Rooms VIII, X, XVI and XVII, the southern block of the complex (Rooms XI and XV) seem to have floor planes directly atop, and even cutting into, medieval levels.

50The analysis of the load-bearing walls oriented north-west–south-east (USM 1037 and 1185) suggests that these are structures of the late 16th cent., pertaining to the first phase of the Alessandrino Quarter. This is also corroborated by comparisons with contemporary examples such as S. Adriano, apart from the masonry technique (characterised by the use of tightly packed, cut blocks of tufa, laid pseudo-horizontally and alternating with layers of bricks on the faces).

51The third excavation phase will be initiated in April 2022. The current field of excavation will be expanded further to the north, and excavations will continue within the current field. This will permit an investigation of the already uncovered structures. However, the excavation will also address a number of unsolved questions in regard to the underlying earlier phases. The eastern side of the Forum of Caesar has not yet been investigated, as noted previously. Since it has not been investigated, it is usually reconstructed with a double portico, following the same dimensions and structural characteristics as the portico on the opposite side. The only archaeological data are those which emerged during the preparatory excavation, prior to the installation of the lifting platform, carried out in 2016 close to the south-western corner. On this occasion, some slabs of white marble belonging to the paving of the external aisle of the portico were encountered. These confirmed that the paving was of the same type as that of the western portico. The nature of the boundary wall separating the Forum of Caesar from that of Augustus is not known. Neither do we know whether there were any connections between them, and if so, how these would have been articulated.

52The area which will be investigated in the coming phase is of particular interest, not only due to the reasons mentioned above, but also because it will unveil a rich urban stratigraphy reaching all the way back to the most ancient human activity. The reason for this is that the area, which will be excavated, is situated on the edge of the saddle of the Quirinal Hill, which was partly removed by Caesar and eventually completely removed by Domitian. The excavations below the Imperial level will thus permit us to reconstruct the variations in the use of this area from the Late Bronze Age until the Iron Age. Furthermore, it will be possible to retrieve important data related to the Archaic period, thus allowing for a clearer definition of the urban layout of this area, characterised by domus a corte (courtyard houses) delimited by a road system, which was not known before the excavations of 2008[47]. The findings expected under the basements of the modern buildings currently occupying the area are equally important. These are the traces of the domus terrinee of which remains can be seen on the western side of the area of excavation.

53The main focal point of the excavation as conducted so far has been to document structures from the last phase of the Alessandrino Quarter in detail, since this is an overlooked chapter in Rome’s archaeology and history. The project team has carefully excavated and documented all remains from this period from a twofold perspective: Firstly, little is known about the archaeological reality of the vast majority of the past Alessandrino Quarter. This is the natural consequence of the rapid pace with which the buildings were demolished in the early 1930s and the general development of Rome from this period onwards. A pace which left little time for documentation of any sort of what was considered an insignificant part of Rome’s long urban history at this point in time. In contrast, The Caesar’s Forum Project differs from past approaches in attributing equal priority to all chronological phases in the area of Caesar’s Forum with regard to both excavation method, documentation and scientific publication. Secondly, whereas a principle of equal priority is applied on the issues cited above, the same principle cannot be projected to the question of removal of structural remains vs. preservation and on-site conservation. Naturally, recent structures must be removed in order to facilitate a comprehensive archaeological reading of an archaeological site that covers 3000 years of urban development.

54The excavation has shown that the architectural structures in this sector of the Alessandrino Quarter were the object of a single action of demolition and levelling, which was conducted in a short timespan here as well as in the rest of the Alessandrino area[48]. Upon these interventions, a general levelling was conducted in the area. Finally, remaining voids on the surface were infilled with soil resulting in a uniform horizontal area. The excavations carried out so far, supported by historical cartography and updated architectural surveys, show that the domestic houses were constructed in accordance with a precise urban layout, in which they were aligned in a north-west–south-east orientation along the now vanished Via Cremona and Via Bonella[49]. Within the excavation field all structures were covered by a soil accumulation (US 1001), which contained frequent finds of recent building material, such as bricks, roof tiles, lumps of cement and wall plaster. US 1001 was deposited directly on the floor levels, and the contextual excavation as well as trench profiles reveal that the material was deposited on one single occasion.

55The documentation of the excavation progress and findings, both in regard to structures and individual archaeological contexts, was supported by the application of total station, GPS and photogrammetry. In addition, to ensure a direct and easily accessible graphical documentation of the excavation, the application of this all-round digital registration permits the team to conduct a precise estimate of the quantity of soil to be removed during the third phase of excavation. This is of notable value for planning the time schedule of an excavation, which is located in one of the busiest areas of central Rome, a circumstance which imposes limitations on access for heavy vehicles to and from the excavation site. The precise quantitative estimates of soil have likewise proven a helpful tool with regard to budgeting the removal and final deposition of soil in landfills outside Rome. On another note, the comparison of the levels between the 1998–2000 excavations immediately to the west of the current excavation and the ones obtained from the original 16th-cent. basements within the 2019 excavation field allowed some assessments regarding the stratigraphic reliability of the levels below the basements. These show that the possible architectural continuation of the domus terrinee structures might have been partly compromised by the construction of the basements. However, this only regards the upper parts of the wall structures, whereas the lower parts and related archaeological stratigraphies should almost certainly be preserved. The technical architectural analysis shows that all walls – except for a few subsequent additions (USM 1036 and USM 1046) – were constructed on one occasion, and that they are related to one single building. The chronological coherency of the walls is clearly reflected in the masonry technique: In all cases the external and internal surfaces are constructed by clamped brick, and the same type of bricks are also often used transversely, forming supportive connections between internal and external walls. The wall fill consists of tufa stones and a high quantity of cement of medium quality. The abundance of cement gives it a function of independent wall fill rather than stone mortar. The mortar of the brick walls is likewise of medium quality, but in a few instances (USM 1027 and USM 1029) a notably better mortar containing pozzolana was used.

56The comparison between the walls brought to light by the excavation and the archival cartographic documentation allows for the archaeological identification of all the walls and confirms a correct spatial positioning of the building structures within the excavation field. This has been of obvious importance during the planning of the next campaigns.

The Caesar’s Forum Project, initiated in 2017, aims at covering the entire more than 3000-year chronological span of the Caesar’s Forum area. The first phase of the archaeological investigations has unearthed structures in the archaeologically under-researched Alessandrino Quarter, which was demolished in order to make way for Mussolini’s Via dell’Impero. This article presents the first detailed overview of the second excavation phase undertaken within the new Danish-Italian project and the new archaeological insights brought to light.