For most of its history, it was the largest and most important province of the Empire, containing key cities such as Edirne, Yanina (Ioannina), Sofia, Filibe (Plovdiv), Manastır/Monastir (Bitola), Üsküp (Skopje), and the major seaport of Selânik/Salonica (Thessaloniki).

From its foundation, the province of Rumelia encompassed the entirety of the Ottoman Empire's European possessions, including the trans-Danubian conquests like Akkerman, until the creation of further eyalets in the 16th century, beginning with the Archipelago (1533), Budin (1541) and Bosnia (1580).

[6] At the time, the beylerbey of Rumelia was the commander of the most important military force in the state in the form of the timariot sipahi cavalry, and his presence in the capital during this period made him a regular member of the Imperial Council (divan).

:[5] The Çingene, Müselleman-i Kirk Kilise and Voynuks were not territorial circumscriptions, but rather represented merely a sanjakbey appointed to control these scattered and often nomadic groups, and who acted as the commander of the military forces recruited among them.

[5] The Pasha-sanjak in this period comprised a wide area in western Macedonia, including the towns of Üskub (Skopje), Pirlipe (Prilep), Manastir (Bitola) and Kesriye (Kastoria).