A reconsideration of early Ottoman history by two young Harvard historians. After reviewing the sources, Turkish, Byzantine, and Arabic, they discuss the development of the Turks in Anatolia, and the early Ottomans in particular, under several lights. The Anatolian Turks began as nomads, coexisting with the urban settlements as nomads have always done. The early Ottomans were among them as vassals of the Seljuks (here Langer and Blake contest the account of H. A. Gibbons), and prevailed when their empire collapsed; there were several reasons for this success. The Ottomans held a frontier upland; their territory was secure, but could easily be expanded by taking Byzantine cities which were in no position to resist; they were supported by dervish orders, which expressed the Messianic Islam of Central Asia; and their military success can be connected with the local organizations or guilds called ahl which existed in Anatolia from Greek times, and which gave notable hospitality to travellers; Ibn Batutta stayed with them during his visit to the peninsula.