A Turkish people who in the 10th century, headed by a chief named Seljuk (whence their name), broke away from their allegiance to the khan of Kirghiz, adopted the Mohammedan faith, and subsequently conquered Bokhara, but were driven across the Oxus and settled HI Khorassan; under Toghril Beg, grandson of Seljuk, they in the 11th century won for themselves a wide empire in Asia, including the provinces of Syria and Asia Minor, whose rulers, by their cruel persecution of Christian pilgrims, led to the Crusade movement in Europe. The Seljuks were in part gradually absorbed by the advancing Mongol tribes, while numbers fled westward, where they were at length incorporated in the Ottoman Empire in the 14th century.