NICAEA325 PROJECT - ARCHEOLOGICAL REPORT

VEROLI FOUNDATION ARCHEOLOGICAL RESEARCH

NICAEA 325 PROJECT

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Our foundation Veroli, was established two years ago in Poland in Wrocław, although our interest in the topic of the First Council of Nicaea within the context of archaeological research predates its founding. Bringing together researchers and enthusiasts from various academic fields, we launched  the Nicaea 325 research project, dedicated to locating the palace of Emperor Constantine, where the council convened exactly 1700 years ago. In addition to the imperial palace itself, our investigation also encompasses other material culture sites associated with early Christianity in İznik and its surroundings. Through this collaborative and multidisciplinary effort, we hope to shed new light on the historical landscape of the region and contribute valuable insights to the understanding of its formative role in Christian history.

Written sources have enabled researchers to put forward seven main hypotheses regarding the location of Emperor Constantine’s palace, which has yet to be discovered.

1. 1.On the Shore of the Lake:
   The first hypothesis suggests that the palace may be represented by ruins situated at the junction of land and lake to the west of the city walls. Although these structures date to the Byzantine period and incorporate architectural spolia from various eras, their origins remain uncertain. This concept, rooted in local tradition since the early 20th century, continues to appear in contemporary studies, despite a lack of clear authorship or scholarly foundation.
2. Near the Northern City Gate:
   Based on written sources and the identification of the palace’s audience hall with the Church of the Holy Fathers, this hypothesis draws upon records by Theophanes the Confessor, who described damage to the city walls near the church during a siege. Subsequent repairs, evidenced by inscriptions and reused marble spolia in the fortifications, suggest the presence of a significant complex in this area.
3. Adjacent to the Church of Koimesis:
   In 1575, Lutheran chaplain S. Gerlach reported a conversation with the Bishop of Nicaea, who indicated that the site of the Council’s proceedings was near the Church of Panagia (likely Koimesis). This implies that in the sixteenth century, the location of the Council was believed to be in the southeastern part of the city.
4. The Roman Theatre:
   At the turn of the 17th and 18th centuries, P. Lucas, envoy of Louis XIV, documented local traditions identifying the council’s meeting place with the ruins of a semi-circular stone structure, interpreted as the Roman theatre. The area, known as Saraybahçe (“palace garden”), may preserve memories of an ancient residence.
5. On Maltepe Hill:
   Located in the eastern part of the city, Maltepe Hill contains remnants of large stone walls, decorative architectural fragments, and mosaics. The name itself (“hill of treasures”) alludes to historic finds and has inspired speculation about the palace’s location in this area.
6. In the City Centre Near Hagia Sophia:
   Urban analysis reveals that İznik’s layout still reflects the ancient Hippodamian grid, with the intersection of main axes traditionally reserved for administrative buildings such as the palace. The proximity of the Hagia Sophia church, likely built on the site of a pagan temple, supports this hypothesis.
7. Outside the City Walls, on the Lake Shore:
   This hypothesis is based on the discovery and study of a basilica located outside the city walls, which until two years ago was submerged under the lake due to previously elevated water levels. Recently, however, the basilica has emerged, as the water level has receded. The site, likely dedicated to St. Neophytos, features a narthex and atrium.

The primary objective of the Nicaea325 project is to verify the hypotheses regarding the location of the site—the audience hall of the palace—where the First Council of Nicaea convened in 325 AD.

Among the proposed concepts for the location of this significant structure, some areas are impossible to investigate due to contemporary urban development that now covers those places. However, our particular focus has been directed toward hypotheses number 1 and 7, centered around the basilica, owing to its exceptional research potential. We have conducted a series of surveys and investigations along the eastern shore of Lake İznik as well as the western part of the city, employing the most advanced technologies available. The results of these studies have proven to be exceptionally intriguing.

For these reasons, the first step undertaken by the Veroli Foundation, beginning in 2023, was to provide financial support for the research on the formerly submerged basilica led by prof. Mustafa Sahin and his team. This support covered underwater investigations, conservation of the structure, as well as archaeological excavations and conservation of the Christian burials located within and around the basilica.

In the initial stage of our project Niacaea325, in coopertion with prof. Sahin, we created a multi-layered documentation of the western part of the city and its surroundings, with particular focus on areas identified for investigation in hypotheses 1, 2, and 7. Our work began with digital imaging of the topography and shoreline of the lake, the identification and mapping of now-vanished streams and water reservoirs, the urban layout of the city, the location and form of architectural heritage structures, and the recognition of previously unknown historic sites. For this purpose, modern technologically advanced mapping and measurement functions were used, i.e. photogrammetry, LiDAR, thermal imaging, and multispectral imaging. Their basis is the use of drones with interchangeable components (RGB camera, scanner, thermal camera, multispectral camera), which allow for quick and effective search of large areas from the air, documentation of the area, and comprehensiveness of activities. At this stage, we employed these advanced techniques to ensure rapid, efficient, and holistic fieldwork.

These investigations were conducted both on land in the western part of the city and, as far as possible, along the adjacent lakeshore zone. As a result, in addition to the objectives outlined above, several significant findings were recorded, including the presence of an ancient bay – presumably functioning as a port – the mouth of a now-vanished stream (possibly the so-called stream of the 318 Fathers), remnants of previously unknown submerged architectural structures and graves, as well as anomalies that may reflect the presence of buried architectural remains.

The research also covered the area around the northern city gate, where proponents of hypothesis number 2 have suggested the Nicaean palace may have been located. This site has acquired new significance due to the architectural relics uncovered there in recent years as a result of conservation work. However, these newly revealed structures have not yet been considered in the context of the possible location of the Nicaean palace.

Subsequent activities focused on creating 3D models of the fortification walls in the southwestern part of the city using the method of photogrammetric scanning. The data obtained through this process form the basis for chronological analysis of the various construction phases of the city walls in this area. This is particularly important for verifying the hypothesis concerning the possible location of the palace in this part of Nicaea.

The next stage of our work focused on the lakeshore zone west of Nicaea. The objective was to record the shape of the lakebed and identify any historic structures lying on or beneath it. For this purpose, we used a multibeam sonar system. This device emits multiple sound beams that, upon encountering obstacles, are reflected back to the receiver. By measuring the return times of the sound waves, a highly realistic three-dimensional image of the lakebed is generated, providing detailed information on its topography and depth.

Through these surveys, we discovered new architectural structures concealed beneath the surface of the lake, previously unknown and unrecognized. Some of these features are clearly remnants of built architecture, which we intend to investigate and identify in the near future.

During this archaeological season, we conducted non-invasive research focusing on material remains located in selected areas of the city. We analyzed collected ceramic sherds, identifying their origin and period of production. Additionally, we surveyed subsurface architectural structures on land in locations associated with hypotheses 1 and 7 regarding the possible sites of the Nicaean palace.

For this purpose, we utilized ground-penetrating radar – a non-invasive geophysical method that enables the creation of three-dimensional images of buried heritage structures, along with data regarding their depth. This approach allowed us to gain valuable insights into the presence and characteristics of subsurface features without disturbing the archaeological context.

All research conducted to date by our Veroli Foundation has led to a series of interesting discoveries, including the identification of previously unknown architectural structures and the verification of several hypotheses regarding the location of the palace. We now know that the palace is not situated in the area known as Seanato Saray, nor by the basilica, nor in the region of the so-called inflection of the fortification walls.

Our next steps, planned for the upcoming archaeological seasons, will focus on thoroughly investigating the remaining hypotheses. Thus, the imperial palace still awaits discovery! In the course of our search for the palace, we are confident that we will uncover many other exceptional and fascinating objects and monuments of material culture.

Detailed information on the survey of historical sources dedicated to the First Council of Nicaea and the location of the imperial palace, as well as the fascinating interview “What happened 1,700 years ago in Nicaea” with prof. Henryk Pietras, PhD, SJ, and further details of our research including a photo gallery, are available on our website: veroli.org

NOVEMBER 28 th, 2025 – Pope’s visit in Iznik