Humble Beginnings and the Rise of the Ottoman State
The core of the Ottoman state was a small principality (beylik) around Sbgut in northwestern Asia Minor, founded shortly before 1300 by Osman.[1819] Its founder originated from a family of Turcoman military commanders and initially served under the Seljuk sultan of Rum (centered in Konya).
Having benefited from the internal crisis of the Seljuk state and the contest between the Seljukids and the Ilkhanids (Mongol rulers of Iran) over the control of Asia Minor, Osman carved out a sovereign state on the western marches of the Seljuk sultanate and began to mint coin in his own name. The composition of Osman's troops and the character of his rule are still disputed by historians,[1820] but it seems that he skillfully combined charismatic leadership with pragmatic skills of a state builder. No less complex was the confessional character of the early Ottoman state. On the one hand, the Ottoman rulers exploited the religious slogans of Muslim holy war,[1821] yet on the other hand, they gathered a heterogeneous host of followers under their standards, including Byzantine Greeks and other non-Muslims.[1822] This complex reality is best reflected in the marriage policy of the early Ottomans: while Osman married a daughter of a Sufi sheikh Edebali, thus securing the support of a charismatic Muslim religious leader, in 1346 Osman's son Orhan married Theodora, the daughter of John Kantakouzenos, the pretender to the throne of Constantinople and the future Byzantine emperor.The rise of the Ottoman state in Asia Minor was marked by the conquests of Bilecik (1299), Bursa (1326), Nicaea/Iznik (1331), and Nicomedia/Izmit (1337)— important urban centers of the Byzantine Empire. In 1352, the Ottomans set foot in Europe, benefiting from the Byzantine civil war, and in 1354 established their rule in the strategically important fortress of Gallipoli/Gelibolu. After the conquest of Adrianople/Edirne in 1361 (or 1369, as alternatively suggested[1823]), the Ottoman sultan and court alternatively resided in Bursa or Edirne, depending on the actual political and strategic priorities. The extension of the state onto two continents also resulted in the administrative division and the formation of two large provinces (eyalets), Anatolia (Anadolu) and Rumelia (Rumeli), which were further divided into smaller sanjaks.
The collapse of the Serbian Empire founded by Stephan Dusan (d. 1355) and the crushing Ottoman victory over the Serbian troops at Chermanon on the Maritsa River (1371) enabled further Ottoman expansion into Macedonia, western Bulgaria, and southern Serbia. As a result of the battle of Kosovo (Kosovo Polje), fought on June 15, 1389, the rest of Serbia was reduced to vassalage.