Eyalets, also known as beylerbeyliks or pashaliks, were the primary administrative divisions of the Ottoman Empire.

Beylerbey was a high rank in the western Islamic world in the late Middle Ages and early modern period, from the Anatolian Seljuks and the Ilkhanids to Safavid Empire and the Ottoman Empire. Initially designating a commander-in-chief, it eventually came to be held by senior provincial governors. In Ottoman usage, where the rank survived the longest, it designated the governors-general of some of the largest and most important provinces, although in later centuries it became devalued into a mere honorific title. The title is originally Turkic and its equivalents in Arabic were amir al-umara, and in Persian, mir-i miran.