The theater, which once hosted gladiator fights, was later used as a religious space after the prohibition of theater following the rise of Christianity. Damaged in the major earthquakes of 358, 362, and 368, the structure was repaired and some of its parts were dismantled for the strengthening of the city walls as İznik's defense.
Excavations in the Roman Theater began in 1980 with the permission of the Ministry of Culture and Tourism. Since 2015, the excavation works have been carried out by a team led by the Department of Archaeology at Dokuz Eylül University, with the involvement of the Metropolitan Municipality.
The excavations, led by Assoc. Prof. Dr. Aygün Ekin Meriç from the Department of Archaeology at Dokuz Eylül University, are conducted under the presidency of the İznik Museum Directorate.
