Özet:

Hereke is a town which is located to the west of Kocaeli Körfez District. Established in the period of 1842- 1845 during the reign of Sultan Abdülmecid, Hereke Weaving Factory (Imperial Factory) was expanded through  integrating new facilities over time, which promoted economic and social life in the town. Hereke Fabrika-ı  Hümâyûn (Imperial Factory) Mosque was one of the social service facilities that were established in addition to  the industrial units of the mill. The mosque was renamed as Sümer Mosque after the mill had been transferred  to Sümerbank during Republican period. Sultan Abdülmecid had the mosque built between 1850 and 1851  to meet the worship needs of the mill workers. Owing to the slope of the land, it possesses an asymmetrical  plan and it is made of masonry material. A flat wooden ceiling was used to cover the inside and a roof for the  outside. The researcher examined on-site and took photographs and measurements of the mosque. The building  surveys, restitution and restoration projects of the mosque were also reviewed. The archive sources were  obtained from General Directorate of Foundations and Turkish Presidency State Archives of the Republic of  Turkey- Department of Ottoman Archives. In literature, there has not been a thorough study on the structure.  In this paper, both the early and late phases of the mosque starting from its establishment will be explained in  chronological order and the changes and restorations will be presented in the light of the available data and in  accordance with scientific criteria.