In the underwater excavation of the sunken basilica (a large church structure) located in Lake İznik in the İznik district of Bursa, it has been determined that this structure was damaged in a major earthquake in the 11th century.
The basilica was discovered 10 years ago, 20 meters off the shore of the lake and at a depth of 1.5 to 2 meters.
The scientific advisor of the excavation, Prof. Dr. Mustafa Şahin, the Head of the Department of Archaeology at Bursa Uludağ University, stated that the basilica, whose existence was revealed thanks to aerial photographs taken in 2014, is a globally significant discovery.
Emphasizing that the basilica holds much greater importance than previously estimated for the Christian world, Şahin noted:
“The data we have obtained suggests that the First Council, which is very important for Christians, may have convened in this area. This council was held in İznik in 325 AD through the initiatives of Emperor Constantine, where the fundamental principles of Christianity were accepted. Among these principles were important decisions such as the divinity of Jesus Christ and the timing of Easter. The First Council is a significant meeting recognized by all denominations of Christianity. The 1700th anniversary of the First Council will be celebrated in 2025, and such historical anniversaries are highly regarded in the Western world. As a result of our excavations, we have determined that the basilica was built after the year 390. Although the basilica was not the site of the First Council, we believe it was constructed here based on the possibility that the council convened in this area.”
Prof. Dr. Julia de Sigoyer, a geologist from the University of Grenoble Alpes in France, who is among the experts involved in the underwater excavation, reported that they have been working since 2018 to identify the major earthquakes experienced by İznik and its surroundings.
She emphasized that they aimed to uncover which earthquake damaged the basilica and made significant discoveries regarding seismic movements, stating, “We discovered that the basilica was destroyed as a result of a major earthquake in 1065. Additionally, we found that there have been no significant earthquakes in İznik and its vicinity since 1065. According to the data, a major earthquake occurs every 900 to 1000 years. Considering the earthquake in 1065, there is a possibility of a significant earthquake occurring in İznik in the near future. We have identified an active fault line in Lake İznik, which indicates the potential for future earthquakes in the region.”