The capture of Adrianople, followed by other conquests, brought about a coalition under the king of Hungary against Murad, but his able lieutenant Lalashahin, the first beylerbey of Rumelia, defeated the allies at the battle of the Maritsa in 1363.
Zeno states that in the following year Ismail entered upon a new campaign in Kurdistan and Asia Minor, but that he returned to Tabriz without accomplishing his object, having been harassed by the tactics of Ala ud-Daula, a beylerbey, or governor in Armenia and parts of Syria.
Before the reconstitution of the provinces as vilayets it was the official title of the principal eyalet of Asia Minor, and was also used more generally to include all the peninsular provinces over which the beylerbey of Anadoli, whose seat was at Kutaiah, had the same paramount military jurisdiction which the beylerbey of "Rumili" enjoyed in the peninsular provinces of Europe.
Arouj seized Algiers (1516); Khair-ed-Din, succeeding him in 1518, did homage for his conquest to the sultan at Constantinople, who named him beylerbey and sent him soldiers (1519).
Under the Turkish dominion Algeria had originally at its head a beylerbey resident at Algiers.