Orhan, also called Orhan Gazi, Orhan also spelled Orkhan(born 1288—died 1360) the second ruler of the Ottoman dynasty, which had been founded by his father,Osman I. Orhan’s reign (1324–60) marked the beginning of Ottoman expansion into the Balkans.
Under Orhan’s leadership, the small Ottoman principality in northwesternAnatolia continued to attract Ghazis (warriors for the Islamic faith) from surrounding Turkish emirates fighting against Byzantium. In 1324 the Byzantine town of Brusa (later Bursa) fell to the Ottomans, followed by Nicaea (modern İznik) in 1331 and Nicomedia (modern İzmit) in 1337.