Squadron of soldiers of the Ertuğrul Cavalry Regiment of the Imperial Guard, Istanbul. "Une Escouade de soldats du régiment Erthogroul de la cavalerie de la Garde Impériale" From Abdulhamid II Photograph collection, photographed by Abdullah Brothers between 1880 and 1890, Istanbul. Abdulhamid II collection is a monumental photograph collection that portrays Turkey during the reign of Sultan Abdulhamid Khan II.