Building in the city. From archaeological markers to the historical reconstruction of the worksite. Some examples from medieval Rome

The present paper considers the topic of building cities. This is certainly a well-studied topic, but also a complex one because different factors are involved with regard to the economic, social and political context, often characterized by the appearance of new main characters. This complexity can be analyzed in many manners, including the one of the archaeology of production and building activities. 
Starting from the considerable amount of data in the database created between 2013 and 2014 for the project “archeologia della produzione a Roma” (Archaeology of production activities in Rome), the topic will be discussed from a point of view considered particularly interesting: the study of archaeological markers in building materials, and therefore, the study of all those production processes involved in construction activities. 
The research will demonstrate how the analysis of physical markers of building activities can record important tracks on different aspects of building, aspects of extreme interest for understanding the city.


FOREWORD
The construction of medieval cities is certainly a well-studied topic, but also a complex one because different factors are involved with regard to the economic, social and political context, often characterized by the appearance of new main characters. The transformations in a city are the result of complex changes, determined by focused choices made by secular and religious powers, sometimes by the euergetism of private citizens, with regard to several elements, such as the defence of the city, the addition of new political/administrative centres, and the Christianization of the city. For each one of these elements, however, an important role is played by the architecture and, therefore, the urban setting. The former constitutes an important marker of economic development, being the result of a series of production processes but also of an investment. About the latter-the urban setting-buildings often become a relevant point of urban reference-think, for instance, of churches, palaces and houses of rulers-and this urban setting is also frequently the result of projects modifying and redesigning the city. In addition, by considering the places of building activity from a topographic point of view, these show relevant patterns in the urban development and in the choices made during the growth of the city. One more extremely interesting factor consists of all the information found on buildings "in negative", if one may say so, that is, all the organized, or not, activities of demolition and recycling of building material, characterizing several parts of the city between the fifth and fifteenth centuries, that must necessarily be connected to the systematic reuse of ancient building material and can be actually seen in all the techniques adopted in Rome in the chronological period considered 2 . 1 This study was a continuation of some of the lessons taught during the Course in Medieval Archaeology at Tor Vergata University in 2018/2019; the lessons regarded the Archaeology of production activities, building materials, construction site activities and in general all the activities related to the construction of a building. In particular, by adopting the city of Rome as an example, the teaching goal was to explain how it is possible to study a city through archaeological markers of construction activities and what kind of starting point for research this type of study approach could be. A database was used for the preparation of classes and also of this paper, created by the author of the present paper for the project "Archeologia della produzione a Roma" (archaeology of production activities in Rome) and free to consult on the CD attached to the volume "Archeologia della Produzione a Roma" edited by A. Molinari, R. Santangeli Valenzani, L. Spera. To this end I'll only take into account archaeological markers of construction activities from archaeological excavations in order to endorse this point of view. 2 For Roman building techniques reusing ancient building material there is a wide bibliography available and only some major studies will be referenced: Avagnina et alli 1977;Barkley Loyd 1985;Esposito 1997;Cecchelli 2001; Meneghini Santangeli Valenzani 2004; Barelli et al. 2005.

THE PROJECT "ARCHEOLOGIA DELLA PRODUZIONE A ROMA": A DATABASE OF PRICELESS VALUE.
The data considered in the present paper largely comes from a database created for the project "Archeologia della produzione a Roma" 3 (Archaeology of Production Activities in Rome), a project started from the idea of an exhaustive analysis on production activities in Rome from the fifth to the fifteenth centuries 4 ( fig. 1). This analysis allowed, for the first time, including Rome within that complex debate on the archaeology of production activities and the different aspects of research that are connected to it. In order to obtain this goal, a thorough survey was conducted on all old and new archaeological data, often rich in information on production activities. This type of data had never been read from the point of view of a city system. The systematic collection of all this data was therefore started through bibliographic research and the consequent classification of all data found. The information was then inserted into the database and into a GIS system of the city of Rome and its closest suburban area, containing about 600 markers of production activities. This survey allowed then, and, as will be seen through this paper, still allows analyzing phenomena of production activities with better accuracy, quantifying them in the long-term and studying them in their context. The opportunity to also look at the topographic connotation, both in the short and long term, allows for considering the complexity, distribution and quantity of the different phenomena, all within the growth and development dynamics of the city between the fifth and the fifteenth centuries 5 . The choice of analyzing on the long term the economy of Rome throughout its production activities allowed for identifying better the phases of change and transition, and the importance of social and institutional transformations for the evolution of economy itself. After all, the final goal of the research was the historical long-term reconstruction of the production processes of the city and of its miles IV-V suburbs, in order to better understand the interactions between urban and suburban areas.

THE DATABASE AND GIS OF BUILDING ACTIVITIES IN ROME: A STUDY APPROACH DEVELOPMENT AMONG TRENDS AND THE STATE OF THE FIELD
In order to better understand the object of the present paper and the potential shown by this kind of research project, a short foreword is necessary on the software that was developed for the collection of data. To obtain this result the data was at first collected with the use of data sheets, which allowed quantifying the information then included in the database and the GIS ( fig. 2).
In particular, the sheets used included different predetermined fields and were based on a breakdown of the production cycle into phases. The database was made with the software Access, while the GIS with the desktop application QGIS (Molinari Gianni 2015). The database was developed through the elaboration of relational tables and masks to help the frontend for data filing. These were then georeferenced into shapefiles with specific datasets of information.
Since, however, the transfer of data into a GIS software requires applying a specific methodology, the risk was scattering the complexity that characterizes the different production activities. Particular attention was therefore given to the transfer of data and to the critical issues brought by the published data.
The smallest recording unit adopted was the marker of production activity, which becomes valid according to the three criteria formulated by Galinié in his work in 2000: locating, chronology, definition, all elements that according to the author rightly define the life of what he refers to as historical objects and that Lefevre identifies as Constituent Element (EC) (Galiniè 2000;Lefevre 2012, 65-82).
In organizing data, both according to quantity and quality, the starting point was obviously to identify these conditions, always considering that the archaeology of production activities must not be really considered, at least not only, "from the point of view of ancient times, but by answering the rather more complex and articulated question of how the objects of the past can be studied with the aim of reconstructing histories on a larger scale" (Giannichedda 2006, 9).
The device used by the workgroup for research had to elaborate information on the organization of spaces, the kind of production contexts and, if possible, the organization and division of work (single or partner workshops, complex studios, manufactures, etc.), at least potentially 6 . In the light of what has been summarized 7 here, it is evident that the analysis, once started, can move with more agility in the complexity of production activities; it also works as a valuable database for the many other researchers who may start from the information offered, as will soon be discussed here 8 .

BUILDING THE CITY: ARCHAEOLOGICAL MARKERS AND URBAN TRANSFORMATIONS.
The availability of such an amount of data on production activities for an urban context such as Rome also allows reading them in relation to the urban development. Looking at the information on building activities in the time range between the fifth and the fifteenth centuries not only gives the opportunity of studying the "geography of production", but also the growth and development phases of the city, especially because about 50% of the information contained in the database regards markers of building activities ( fig. 3). This evidence ranges from the identification of quarry sites, to spoliation pits for the recovery and reuse of building materials, to lime kilns, to heaps of materials always tied to calcination activities, to evidence on site connected to larger or smaller worksite activities of both building and dismantling; all extremely interesting data in detail, and even more so if we try to interpret them in a diachronic way, or in relation to what has survived of Roman medieval buildings. To demonstrate how these constituted focal points in the growth of the city, brief chronological summaries will be offered.

6
A possible limit of the database, of which we were aware from its beginning, is that it contains only archaeological evidence. In my opinion, tracks of production activities must be related to the different phases of a production cycle in order to not be misinterpreted, without overlooking the information coming from other kinds of sources that describe, for instance, production manners, the introduction of technological innovations, and the use of particular materials. These reflections led to associating data across topographic contexts, once the marker was identified as a minimum unit. 7 For a thorough examination of the system see Giannini 2015. 8 Following this paper is a bibliography on methodology and also regarding specific case studies. In retracing the thoughts that led to these considerations, only some of the main publications will be referenced, fil rouge of the system developed and of the archaeological questions that this paper tried to answer. On the study approach on production activities and on their related issues see Whisky 1962;Carandini 1979;Mannoni 1993;Giannichedda Mannoni1996;Gould 1997;Lugli, Stoppiello, Vidale 2000, 17-19;Carver 2001, 1-22;Mannoni 2002;Vidale 2004;Mannoni 2004, 545-550;Forster, Cross 2005;Giannichedda 2005  Late Antiquity (5-7th centuries) ( fig. 4). The analyzed data shows that the archaeological markers of the fifth century are quite weak. Few tracks related to brick production and even fewer weak tracks about quarry exploitations were found (Spera-Palombi 2015, 21). The tracks relatable to the production of lime are also few. The small amount of collected information is concentrated inside disused buildings in peripheral parts of the residential area 9 . Interesting also are the finds of  different heaps of marble material 10 in the mausoleum of Augustus 11 and in the villa of the Quintili and in Piazza della Chiesa Nuova, where a pit for slaked lime was also found 12 ( fig. 5). Just as relevant for understanding the development of building activities in this time period are the devices for manufacturing lime, functional to the construction of the church of S. Sisto Vecchio 13 , to the basilica of S. Stefano at mile III of the Via Latina 14 , and those found in the north-west area of the Roman Forum 15 . Also, a structure tied to sporadic working activity was recorded in the storage rooms built under emperor Domitian, in the block included between via di S. Paolo alla Regola, via del Conservatorio, via delle Zoccolette and via dei Pettinari. This was a pit used for extinguishing lime in the floor of one of the storage rooms, datable between the end of the fourth and beginning of the fifth century.
10 These were also often found in association with spoliation pits for the reuse of building materials.  If the situation in the fifth century is challenging to define, the situation does not appear different for the sixth-seventh centuries. It is possible to attribute to this time period a layer of travertine chips found among the ruins of the Forum Transitorium 16 , two lime kilns in the Atrium Veste associated to heaps of marble ready to be baked for the calcination process 17 , the sediments of stone material found in the Flavian Amphitheatre 18 , the heap of marbles found in the area of the Horti Luculliani 19 , the waste coming from a probable structure for the production of lime, found together with two spoliation pits and the remains of two calcination structures, in the domus of Palazzo Valentini 20 and of Palazzo delle Assicurazioni Generali 21 . These are all activities that can be related to dismantling and spoliation worksites, both in the public and private context, such as the domus, all additionally located in the central parts of the residential area 22 . In the context just described, particular importance is assumed by what was found at mile V of the Via Flaminia, close to the Tevere River 23 (Spera-Palombi 2015, 25-26;Palombi 2012, 53-61), where an actual dismantling worksite was found, opened for reusing building material (Esposito 2012, 73-75;D'Amelio Esposito 2012, 331-343) (fig. 6, 7, 8). Evidence of brick production is absent for the sixthseventh centuries, to which only the structure found among the ruins of the balneum of the Frates Arvales can be connected, in the area between miles V and VI of the Via Campana 24 (Loreti, Martorelli 2000, 389).
Early Middle Ages (8th-10th centuries) ( fig. 9). In this time period a noticeable increase of workshops specialized in the manufacturing of lime and marble occurs, located especially in the area between the Palatino Hill and the southern part of Campo Marzio. What appears to be interesting is that most of these activities were included into public buildings, continuing in this way to document the almost systematic process of the spoliation of the city. Among the tracks relatable to the working of marble 25 , and therefore to the organization of the marmorarii workshops, the case of the Basilica Iulia is extremely interesting.
Here, together with other production structures, a circular kiln was found in the central aisle and also several heaps of architectural material, and several tracks of perishable material all around the other markers mentioned 26 . The group of these elements appear to be connected to what seems to be an articulated organization of spaces used for the activities of the production cycle, from the provision of materials, to the reworking, to the transformation on site of the spolia.  In this period there was an increase of data regarding the manufacturing of lime, among which it is possible to find several permanent structures in use for a relatively long time. To these, many structures can be added, interpreted as temporary installations for specific restructuring needs, and some installations made for satisfying the building requirements of specific settlement centres. To the former category belong, besides the previously mentioned lime kiln in the Basilica Iulia, the furnaces found close to  the atrium of the Sant'Elena Mausoleum along the Via Labicana 30 ; in both cases these finds, even if sporadic, bear witness to a clear change in use of the residential complexes that, entirely or in part, were converted into places for production activities.
A case of extreme interest is represented by what emerged from the excavations conducted in the area south of the basilica of S.Paolo f.l.m., which allowed identifying a very long-standing worksite activity dated between the first half of the eighth and the tenth-eleventh centuries, in relation to different building phases of the monastery 31 (Filippi, Spera 2009      associated; tracks tied to the presence of marmorarii workshops, however, are recorded in the Templum Pacis 34 (Spera, Palombi 2015). Between the twelfth and the thirteenth centuries, in connection to the sudden growth of building activities recorded by written sources (Hubert 2000) and to what survived of secular buildings, one witnesses an exponential increase of markers of building activity, where the rise of permanent structures is symptomatic. The distribution analysis of markers concerning lime manufacturing highlights an almost detailed distribution in all the portions of the residential area 35 . Among the structures of greater interest, the ones formed by multiple furnaces stand out, a sign that the area was frequented and used for long term production activities organized into a well-structured worksite. Of extreme interest appears the structure of S. Pasquale Baylon, also located in an area, Trastevere, that saw in this same period a large settlement growth and where, besides permanent production structures, notable tracks of calcination activities have also been found, as well as intentional heaps of spolia, and storage areas (Porcari 2009, 93-129)      The summaries presented, even if concise, allow for underlining from the fifthseventh centuries an ever increasing and more documented reuse of material, tied in many cases to reworking activities. This increase is obviously connected to the abandonment of many buildings and to the considerable changes of use that modified the urban setting and that often prove their conversion into small or medium-sized worksites. The changes in use often document the reuse of especially public buildings. On the one hand this highlights a certain privatization of public areas, and on the other, they recall, since Late Antiquity, the presence of a patron with a promotional function and controlling activities. One other element that emerged was the fact that sporadic structures are side by side with actual dismantling worksites, implying a considerable organization and programming of the same worksites.
A large portion of data is, in fact, related to the recycling of the main building materials, as seen from the several tracks of dismantling and recovery, both in the urban and suburban contexts. These activities are perfectly in line with what was found both in secular and religious buildings, where the systematic reuse of selected, or not, building material occurs during the entire time period considered (5-15th centuries) (Meneghini-Santangeli Valenzani 2004;Esposito 1997, Cecchelli 2001. So, if on the one h and, buildings show the presence of reused material, on the other, many archaeological markers document dismantling and demolition activities which allowed the reuse of building materials. Among these, the largest amount of information comes from all the markers tied to the production of lime. The information in the database highlights how the majority of structures is concentrated in that monumental area of ancient Rome, underlining the close relationship between their presence and the consequent presence of material to calcinate (Santangeli Valenzani 2015, 336). If the impact of these activities on the conservation of ancient monuments was certainly remarkable, impressive was also their economic cost; in addition, especially the greatest dismantling, such as the one of the pavement of the Forum of Caesar removed in a single phase halfway through the eighth century, one can suggest an intervention tied to precise and important building operations, connected to a high level patronage (papal or of the ruling classes), since they took place in areas that were, at least to that moment, public.
If the archaeological markers found do not provide detailed information on the forms of this reuse and on the person managing it, the adoption of this building material, especially in the early medieval period, still shows a clear use in religious and high-quality residential buildings. An evident example is in the opus quadratum technique called "Carolingian", made with reused blocks that were reworked and often reduced in size ( fig. 17, 18). This is a well-studied example, also considered by R. Santangeli Valenzani, which allows a clear reflection on the kind of access allowed to these dismantling worksites, given the kind of buildings where this technique is found; whoever had access could manage the worksite, and, most of all display of amounts of money to invest in these sites. In the light of this, the important role played by the church cannot be underestimated, which certainly acquired more managing and organizing independence between Late Antiquity and the early medieval period for the provision of building material, their  manufacturing, the management of worksites, and the summoning of specialized workforces 50 . It is possible to also add to these activities the management of monuments in the city, which determined in a certain way the consolidation of the pope's political authority (Santangeli Valenzani 2015, 341).
The situation in the following centuries appears different, because some data suggests a change in the managing of monuments, since the spoliation practice, still documented, seems to be more tied to private patrons than in the past, partly in connection to the privatization of public areas in many sections of the city since the ninth century 51 . Moving ahead in time, we cannot avoid associating the archaeological record to what is known about the development of the city.
From the end of the eleventh century the city saw an economic and demographic recovery, intertwined with the birth of the commune-with its significantly complex history-and with the transformations of papacy in this same period. These events put an end to that system of Adelpapsttum or Familiennpapsttum, that brought to the end within the city the identification of the papacy with the Roman aristocracy: the former became a distinct entity from the city and separated, at least in part, from the influence of the important aristocratic families. Therefore, from the second half of the eleventh century, a new urban aristocracy was born, with the establishment of new family groups that were untied from the papacy but also related to it differently (in economic or political ways or through patronage), in line with the economic development of the time; between the twelfth and thirteenth centuries the establishment of the senatorial aristocracy will follow and also a further growth that will turn Rome into a mercantile city.
In conjunction with the events summarized, Rome also saw its most intense urbanization, as documented by the many buildings from this period in several areas of the city. An interesting example in this context is the making of the Marana stream, completed by Pope Callixtus II in the first half of the twelfth century 52 (fig. 19). This canal has already been described in other studies, consultable by the reader, but the present paper will focus only on the structures 50 Think, for instance, of the mortar mixers in S. Paolo f.l.m. or of the one found close to Via Trionfale, elements that suggest the use of specialized building workforces showing the same knowledge of techniques. 51 As shown by the surveys in the area of the Imperial Forums, in many nearby public spaces, orchards, vines and houses were installed. Cfr. Meneghini Santangeli Valenzani 2004. As already underlined by R. Santangeli Valenzani, the houses made in these sections were completely built in reused material and it is hard to hypothesize if they were granted to each owner to obtain the demolition of a monument, or part of it, to recover building material out of it. It is instead more plausible that these demolitions would happen because of the simple property right on the monuments or part of them, because they were inside the owned piece of land. Cfr. Santangeli Valenzani 2015, 341. 52 The "fosso dell'acqua Mariana" or "Marana" is certainly one of the most interesting canals of the Roman Campagna. Already mentioned in sources of the eleventh century as Acqua Crabra (Tab. Santa Maria Nova doc. VIII), it started from the springs in the Latin Valley between Colle Tuscolo and Colle Molara, continued north-west towards the Tuscolano-Artemisio enclosure, crossing the residential area of Grottaferrata and collecting also the springs from the "Acqua Julia". From here it continued towards Valle Marciana under the abbey of S. Nilo and, across an itinerary now matching the stream of Tor Sapienza, joined the Aniene river in the area of Ponte Mammolo. The deviation, attributed to Pope Callixtus II, modified its itinerary in the area of the "villa dei Centroni" on the Via Anagnina, where, through the creating of a sluice, the waters of this river were channeled into the "fosso dell'acqua Mariana" and then towards the Laterano area. created to make the stream pass through the Circus Maximus . The surveys on the hemicycle, started halfway through the 1980s, brought to light a long use of the monument in close connection with water, an element that assumed particular importance in the postclassical period (Brandizzi Vittucci 1991;EAD 1990;EAD 1988) (fig. 20, 21).  Together with these transformations, an open area canalization, paved with architectural reused elements, was also made. This canalization determined the complete defunctionalization of the previous aqueduct and was characterized by a greater water capacity. After this, stratigraphy allows dating to the beginning of the twelfth century the creation of a bank with ceramic material, followed by the making of a sluice and a wall below the bank. The works were part of a real urban plan concerning the entire city and aimed at creating this canal to entirely bypass the city; it is possible, as a matter of fact, to consider the Marana stream as an essential part of what very much resembles a large-scale "urban project" launched between the end of the eleventh century and at least the first three decades of the twelfth century, based on a different way of perceiving spaces and urban elements, where the canalization of water also played an important role. Without considering this project in detail, on this occasion it is particularly interesting to consider the economic connotations of this operation (Guidobaldi 2014;. The deviation of a river is not a small thing; even more so if planned during the wide range of transformations already described, which certainly implied an important financial commitment. We are not currently able to quantify the cost of a similar operation, nor to suggest any interpretation through the use of the given data on the provenance of the money required for it. However, once again, data proves to be of large importance. The modification of the Circus Maximus area for the flowing of more water implied a peculiar building technique that used marble chips. This technique is not found in religious buildings between the papacies of Paschal II and Honorius II, and rather refers to masonry characterized by the presence of irregular flint and marble chips, mainly found in private and defensive structures of the Roman Campagna. The substructure masonry of the found side was made in irregular marble pieces of different dimensions, organized in undulating rows, both convergent and split, and can be compared, for example, to textures ascribable to the first half of the twelfth century 53 . This technique also corresponds, in a certain way, to some restoration of the Aurelian Walls, especially along the southern section between Porta Appia and Porta Ostiense; a portion of the walls closely tied to our stream and also characterized by Porta Metronia, through which the Marana entered the city and where the well-known inscription is on the restoration of the walls by the senate in 1157. If the commune was only formed in 1143, it is, however, true that several documents highlighted, for example, the role of the sexaginta senatores even before this institution officially existed. The transfer of water from the Aniene to the Tevere Valley appears, in addition, to support the commercial connotation of the city, by preserving -as previously explained-the city harbours such as the Magnus harbour, but also by enhancing the area of the Ripa Romea and the section between the Almone and the city. One should also consider that the Via Latina was an important node of the road network towards the south, a factor tied to the distribution of products. After all, if we look at the territory, the area between the Via Latina and the Appian Way is certainly the most productive in the Roman Campagna and, as a consequence, the object of greatest attention for political powers. Think, for instance, of the area surrounding the abbey of S. Nilo, and particularly of the water network of the Valle Marciana, where metal, paper and textile manufacturing is documented in the medieval period, or the mill of Mola Cavona, the Mola de Supra, the Mola Vexalla, or the four mills in the area of Porta Asinaria recalled in the document by Alexander III, and also the millstone of the Porta, mentioned in a document of 1397, or the Molella S. Johannis, property of the Laterano chapter, mentioned in a document of 1426. Finally, one other element inviting to extend the research in this direction is the actual interest of Roman citizens, who will manage many forges in the Valle Marciana during the centuries following this intervention. This interest is confirmed by the fact that between the end of the twelfth century and the beginning of the thirteenth century senatores e mercatores are mentioned in documents, building some houses exactly here, after supporting the destruction of Tuscolo.
These considerations recall a secular connotation and suggest hypotheses, all to be verified, on a possible "secular" participation in the works, in terms still to define.
Later in time, the restart of spoliation activities on a large scale between the thirteenth and fifteenth centuries, -think of the dismantling of part of the cavea of the Flavian amphitheatre, or of the dismantling of almost all of the border walls of the imperial forums, -underlines how, in this case, we can also see vast operations, requiring a large technical commitment, specialized skills, a complex worksite organization, but also important investments -an aspect that once again recalls aristocratic or religious patronage ( fig. 22, 23). The last considerations regard the production of brick. As a matter of fact, the data presented show how tracks of this production are basically missing for the wide time range considered in the present paper. This is not surprising if we think of the reuse of building materials, as seen during the entire chronological period considered.
However, the analysis of the only find of a brick furnace -the one in Piazza Cesariniinvites some interesting considerations (Filippi, 2010, 54) (fig. 16). Despite the little published information on the location of the artefact and on the human activity in the stratigraphic layers associated to it, the furnace appears interesting if included in the panorama of brick production in Rome in the Middle Ages 54 .
The structure was found during the surveys along corso Vittorio Emanuele, for the construction of the Metro C . We are in an important area of the city, that is, the western section of the Campus Martius, an 54 The record related to this production in Rome is still incomplete, despite some existing studies, both for the physical and written sources. For understanding the modes of pre-industrial production in Rome, the treatise by Giuseppe Valadier « L'architettura Pratica» published in 1828 remains fundamental and is rich in information on the description of artefacts, often accompanied by illustrations of furnaces, tools and phases of the production cycle. A first synthesis on brick production in the Lazio region between the sixth and the twelfth centuries was produced in the important work published by Arthur and Whitehouse in 1983 on the brick production of central and south Italy (Arthur Whitehouse 1983, 525-537). At the time, studies on the production in the Roman area were still poor but, in time, archaeological surveys included important acquisitions, many of which were published almost twenty years after the work by Arthur Whitehouse in the Rome conference of 1998, published in 2001(De Minicis 2001. For certain aspects of brick production in Rome and for the case studies here described see Giustini 2001, 9-21, Giustini, 1997, Montelli 2001. For a methodological approach see Steinby, 1993, 139-143, Campagnoli 1993, Mannoni 2000, Ratilainen, Bernotas, Herrmann 2014. For a study especially on written sources see Cortonesi, 1986, Pineiro Vaquero 2002. Finally, among the wide bibliography see Peacock 1979, Norton 1990, Parenti 1994, Pittalunga Quiros Castillo 1997, Parenti Quiros Castillo 2000, Quiros Castillo 2001, Id. 2005, Baldassari, Ciampoltrini 2006, Mellor 2014. area continuously built since the late republican period. The surveys brought to light a sequence of settlements from the Augustan Age to the present, yet showing, in many cases, the lack of fully medieval layers, because they were removed due to the architectural changes in this part of the city, between the sixteenth and seventeenth centuries. However, this same survey brought to light the remaining evidence of the medieval levels dating to the thirteenth-fourteenth centuries, relatable, together with the structure, to the building activities of that period. Undoubtedly, brick production is one of the most important building activities for the city since the Roman period, and certainly highlights an entire set of problems connected to the study of production activities in the medieval period in a city such as Rome (Panella 2015;Coarelli 2015).
The brick industry in Rome, widely documented up to the third century, is first interrupted towards the middle of the fourth century, and then undergoes a new beginning in the Theodorician period (490-526), but never recovering completely to the level of activity documented in the imperial period. Even if the data derived from archaeological surveys signal the presence of manufacturing, especially for roof pieces, it is only towards the end of the Middle Ages that these activities flourish again as a leading economic activity organized serially. Between these two chronological periods, the sixth and fifteenth centuries, there was also a very small recovery supported by the Carolingian popes, while the production patterns between the eighth-ninth and fourteenth-fifteenth centuries still have to be examined thoroughly. If reuse activities are well-known and documented, it is, however, also true that we have knowledge of some production activities, definitely limited and for a short time, during both the early medieval and full medieval period.
Think, for instance, of the brick with stamp Iohannes in a tabula ansata, coming from the temple of Vesta, or of the tiles with the stamp of pope Hadrian I from the roof of S. Maria Maggiore, and also of the tiles with stamp of Innocent II, found on the Via Nomentana (Crostarosa 1896, 63;Steinby 1973Steinby -1974Id. 1986, 146-148, 158-159;Gatti 1909, 107-112;Marini 1884, 5.). These are limited cases that could, indeed, recall the euergetic value of the brick stamp, but could also be framed within the scene of tile production. As already highlighted by E. Hubert, roof bricks seem to turn from a luxury good reserved for few people, between the tenth and eleventh centuries, to a building product newly spread from the twelfth century 55 , so much as to become almost primary in the fourteenth century 56 . In all the cases described, the connection between brick production and papal or ecclesiastic patronage is apparent, also well documented in excavations 55 A definite proof of this economic value is the fact that the cardinal of S. Maria in Trastevere in 1075 exchanges a one-story house with a land and one hundred tiles. (Tab. Vicar. Urbis, Archivio del Capitolo di Santa Maria in Trastevere, perg. 6). According to Hubert, the lack of mention of the topic in written records from the twelfth century is determined by the large distribution, which brought notaries to stop recording the presence of tiles because their use had become common (Hubert 1990, 220-222 e 228-229 of furnaces in Rome, in its territory and in other areas of the Lazio region, such as Montecassino (Pantoni, 1953, 258). Here, research on the technology of production underlined the presence of specific production activities, which seem to correspond with practices typical of the Lombardian area (Giustini 2001,11). Another interesting example is the furnace found in archaeological excavations conducted in the domuscultae of Santa Cornelia, where its products and waste materials could be dated between the eleventh and thirteenth centuries. The structure was put in relation to the production of roof materials for the church 57 . The exclusive presence in the walls of the ecclesiastic complex of reused "tufelli" and bricks support this interpretation, even if perhaps with the newly acquired information on the stratigraphy of the Roman brick buildings, an updated reading of data would be appropriate. The structure invites reflection on the relationship between places of production activities, patrons (ecclesiastic) and materials used. This connection between the production cycle and the ecclesiastic worksite, always in the surroundings of Rome, emerges also in the case of the brick furnace found in the square facing the castle of Julius II, referable to the creation of the episcope wanted by Pius II, inside the town of Ostia Antica, even if dated to the beginning of the fifteenth century (Broccoli 1983, 170-175;Giustini 2001, 13). Production activity is also documented here, comparable to the case mentioned, but also to other structures in the Lazio area. Let's consider, for example, the furnace found in the area of La Fontanaccia-Allumiere, also in close connection with a religious patron and in the proximity of an area characterized by the presence of figlinae in the ancient Roman period 58 . It is definitely still a small number of known structures. However, these show an interesting situation for the chronological period between the eleventh and fourteenth centuries, when, in the light of archaeological evidence, brick production appears to always be tied to ecclesiastic worksites of a certain relevance 59 ; these also show how, next to a wide use of spolia material in the construction of religious buildings, rare examples of new production existed and started growing until they proliferated in the following centuries 60 .
57 The furnace can be compared to the structure found in the church of SS. Giovanni e Reparata in Lucca and dated to the end of the twelfth century. Cfr. Quiros Castillo 2001, 35. It is interesting to remember that, in the light of what is presented in this paper, what the author says about its characteristics: Quiros Castillo underlines how the furnace was made of bricks of a particular module (26x 13x 5 m) and that these can be compared to the bricks used for the church aisles, confirming their creation for the construction of the building. 58 I also consider it appropriate to remind that the data on the section of the Appian Way including the domusculta Sulpiciana is still scarcely studied under this particular research field; for several production features this territory keeps on having a determining role in the evolution patterns of the city. In particular, regarding brick production, the find of a brick stamp of the figlinae Sulpicianae should be remembered, in the area of the Colle Savelli, a focal point of this territory for a long time. On other aspects of production in this zone where the relationship with Rome can be seen Giannini 2006 e ead 2013. For the Roman figlinae and the interest of Roman aristocracy in the economic management of these activities see Coarelli 2015. 59 The relationship between new brick production and worksites of religious patrons is also tied to the presence of a series of technological innovations compared to the Roman tradition, marking in a significant way the study approaches, not only in the archaeology of production activities, but also in the construction of the city. 60 In the light of the context described, it appears suitable to also remind about the structure excavated in 1996 in the site of Rossilli along the Via Latina. The structure found dates back to the 13-14 th centuries, and stratigraphic data highlighted an abandonment of the structure already at the end of the fourteenth century. See on this Giustini 2001, 13.