Metropolis of Nicomedia

Christianity spread to Nicomedia during the middle of the 1st century, while the city became the oldest bishopric established in the region of Bithynia, in northwestern Asia Minor.

[5] From the middle of the 19th century a number of social and political developments promoted the role of the clergy: population increase and economic development of the local Orthodox communities, as well as the enhanced role of the metropolitans as representatives of the Greek Orthodox communities in the provincial administration of the Ottoman Empire, and the thriving of education, mainly through institutions controlled by the clergy.

However, due to developments of the war the Greek Army retreated and the surviving local population evacuated the area.

From the first centuries of the Ottoman period the local metropolis comprised two geographically discontinuous districts, that of Nicomedia and of Apollonias.

The metropolitan district of Nicomedia, apart from the city itself, also included its immediate hinterland as well as the kazas of Adapazarı, Yalova, Karamürsel and Kandıra.

[5] Until 1922-23 the area of the metropolis consisted of 35 ecclesiastical communities, while according to early 20th century estimates the population numbered 43,950 Greek Orthodox people.