Church of the Koimesis

Koimesis Church is a monumental historical structure located in the İznik district of Bursa province. The building, situated in Yeni Mahalle, Çelebi Street, is registered in the records of the Ministry of Culture and Tourism under the name “Remains of Koimesis Church”. Its protection status is classified as “Monumental”, and its environmental protection status is rated as “3”.

The exact construction date of the building is uncertain, but academic research suggests it was likely built between the 7th and 8th centuries. It is accepted to have been located within the boundaries of the Hyakinthos Monastery during the Byzantine period. As one of the major religious centers of İznik in Byzantine times, the structure underwent various phases due to earthquakes and repairs throughout its history. After 1922, it was largely destroyed, and today only fragments of the foundation walls remain.

The Koimesis Church follows a three-aisle basilica plan, measuring approximately 22.5 meters in length and 21 meters in width. The western section contains a narthex, the central area houses the naos, and the eastern end features the bema, apse, and pastophorium. The dome rests on four arches. The surviving wall fragments are currently located approximately four meters below ground level. Constructed using a combination of cut stone and brick masonry, the building is an important example of early Byzantine architecture.

The Koimesis Church is renowned for its early Byzantine mosaics. Mosaic compositions depicting the Virgin Mary and Christ are found in the semi-dome of the apse, while vegetal and geometric patterns adorn the bema arch and the narthex. These mosaics are considered characteristic examples of 7th- and 8th-century Byzantine art from an iconographic perspective.

Today, the structure is largely in ruins. Excavation and cleaning works were carried out between 1955 and 1967 by the İznik Museum Directorate. The architectural elements and mosaic fragments recovered were added to the inventory of the İznik Museum.

The Koimesis Church is regarded as one of the most important places of worship in the Byzantine-era city of İznik (Nicaea). Its mosaics and spatial layout reflect the developmental phases of early Byzantine architecture. The building holds a unique position within the archaeological heritage of Bursa and İznik due to both its architectural features and its iconographic richness.