The oldest Roman city in Bulgaria, founded in AD 70 by veterans of the 8th Augustan legion
Ancient Deultum
Colonia Flavia Pacis Deultensium
Foundation & Location
The Colonia Flavia Pacis Deultensium is the oldest Roman city in Bulgaria, founded in AD 70 by veterans of the 8th Augustan legion. It is one of the two Roman colonies in the province of Thrace, together with Colonia Claudia Aprensis (modern-day Türkiye).
Deultum is located in southeastern Bulgaria, near the modern village of Debelt, approximately 17–20 km southwest of the coastal city of Burgas.
One of the intriguing concepts approached in the project is the “journey” of the legio VIII Augusta members from protectors of the Lower Danube, allocated in Novae, to veterans founders of the Colonia Flavia Pacis Deultensium.
Historical Overview
Ammianus Marcellinus (ca. 330-390’s AD) called the city “oppidum” around AD 377: Barbari… oppidum petivere nomine Dibaltum (Amm. Marc. 30.8.9). The colony flourished during the 2nd – mid-3rd century, quickly overcoming several enemy attacks and internal conflict.
A turning point in the history of the city was a powerful barbarian attack soon after AD 270 – most likely Goths and their allies. The devastation in the colony was so great and the city’s population decreased so drastically that Deultum subsequently reduced its protected area almost six times.
According to the stratigraphic data, this new fortification was erected ca. AD 300 (between AD 297 and AD 313). The buildings that remained outside and around the new fortress were destroyed: e.g., the eastern part of the thermae and the main part of the “Emperor’s temple”.
Architectural elements and gravestones were used as spolia in the new Late Roman fortress. Thus, the powerful enemy assault did not just lead to a significant reduction in the colony’s protected area – especially from the east and the west – but also caused a significant change in its urban planning.
A strong earthquake (t. p. q. AD 351 or AD 353/358) and new enemy attacks made it more difficult for the city to adapt to the profound social changes in the Empire during the Dominate. Many sought protection behind Deultum’s thick fortress walls. People of East Germanic origin were also allowed into the city. The premises of the former public bath were turned into dwellings as well as food warehouses. It seems that Deultum recovered only in the second half of the 5th c. (t. p. q. AD 457), when it almost doubled the size of its late Roman fortress. But the city never reached its original size after AD 270.
The rather elongated outline of the early Byzantine fortress was required for two purposes: to exercise control over the terrace overlooking the northern part of the city, and to protect the port at the Sredetska River to the south, through which, by way of the adjacent Mandrensko Lake, Deultum maintained a direct connection with the Black Sea.
Source: VAGALINSKI, L. 2020: Archaeological Data on Cataclysms in the Roman Colony of Deultum in Southeastern Thrace (2nd – 6th century AD). In: Proceedings of the Fourth International Roman and Late Antique Thrace Conference: Conflicts and Catastrophes in Roman and Late Antique Thrace. Burgas, 12th—16th October 2020 (Bulletin of the National Archaeological Institute, vol. 50), 37-58.
Recent Archaeological Surveys
Although the Roman colony of Deultum has been studied since the 1980s, until recently little was known about its immediate surroundings. Since 2018, field surveys, led by Assoc. Prof. Ivo D. Cholakov (NAIM-BAS), have been carried out on the territory of Sredets municipality using the method of complete coverage of the area.
Field work includes polygon mapping of the surveyed area, collecting pottery fragments and other artefacts, and documenting new archaeological sites. The information is then processed and entered into a common database compatible with ArcGIS. This allows the research team to mark the territory of the newly registered sites and, after analysing the collected pottery, determine their type and chronology. All sites are subsequently registered in the Archaeological Map of Bulgaria.
Since the primary focus of the field survey is the immediate vicinity of Deultum, the image shows the covered area and the registered archaeological sites near the colony.
Two distinctive methods of analysis were further used by a GIS specialist to calculate the possible routes and to reconstruct the main roads on the territory of Deultum – Conduct Lidar and thermal imaging of the area.
In Fig. 1 and Fig. 2 you can see maps of the covered area in the vicinity of Deultum, with a dispersion of ceramic fragments in 2018-2025 and all archaeological sites recorded in the vicinity of Deultum in 2018-2025 (Ivo D. Cholakov, Angel B. Grigorov, Plamena Dakasheva, Ivet Kirilova. Viae ad Deultum: Spatial Perspectives on Roman RoadInfrastructure in Southeastern Thrace. Bulgarian e-Journal of Archaeology, Suppl. 13, 2026).
Digital Documentation & Methodology
Since 2018, all newly excavated sectors of the Deultum’s fortifications have been documented annually through the digital photogrammetry technique. Thus, for all sub-sites there are georeferenced three-dimensional models, orthophoto plans and digital elevation models. The information is further processed so that it is presented in the form of technical architectural drawings with all the necessary designations.
In addition to creating a database on the type and condition of the discovered structures, the documentation prepared in this way is part of an overall architectural survey that aims at creating digital reconstructions of the fortification facilities. The work includes also a careful inspection and analysis of the preserved structures on site and identification of traces of already lost elements, study of parallels, analysis of possible construction schemes.
The Minerva Statue: A Remarkable Discovery
In the course of nearly 40 years of excavations in Deultum, several pieces of an over-life-size marble statue have come to light. The fragments have all been unearthed in secondary context, many of them in poor condition, badly burned. After painstaking examination, the pieces have been assembled together and it is now known that they belonged to a 2nd-3rd century statue of Minerva, identified by her characteristic attributes – an aegis and a shield. It is a variant of the popular Giustiniani Athena type. Notably, the Deultum specimen bears a shield with an unparalleled scene of Gigantomachy, unlike the traditionally depicted Amazonomachy.
So far, this unprecedented monument has been visualized only through a classic four-sided graphic reconstruction. The fragmented state and condition of the statue have prevented its adequate presentation to the audience. It is within the scope of DigiDeultum to use several tools for digital enhancement in order to do justice to this unique monument and tell its story, by displaying it at least digitally at Deultum’s in situ museum.
*The content of this page is based on materials from the presentation “Upgrading the Historical Narrative” by Lily Grozdanova, Sofia University “St. Kliment Ohridski” at Digital Classicist Seminar, Berlin, 2026.