The administrative divisions of the Ottoman Empire were administrative divisions of the state organisation of the Ottoman Empire. Outside this system were various types of vassal and tributary states.
The Ottoman Empire was first subdivided into provinces, in the sense of fixed territorial units with governors appointed by the sultan, in the late 14th century.[1] The beylerbey, or governor, of each province was appointed by the central government.[2] Sanjaks (banners) were governed by sanjak-beys, selected from the high military ranks by the central government.[2][3] Beylerbeyis had authority over all the sancakbeyis in a region.[2] Kaza was a subdivision of sancak and referred to the basic administrative district, governed by a kadi.[2]
It is considered extremely difficult to define the number and exact borders of Ottoman provinces and domains, as their borders were changed constantly.[4] Until the Tanzimat period from 1839 to 1876, the borders of administrative units fluctuated, reflecting the changing strategies of the Ottomans, the emergence of new threats in the region, and the rise of powerful Ayans.[5] All the subdivisions were very unequal in regard of area and population, and the presence of numerous nomadic tribes contributed to the extreme variability of the population figures.[6]