The Seljuks, whom Alp Arslan led, were Turks. They were Sunni Muslims descended originally from nomadic tribes who lived around the Aral Sea (which today lies between Kazakhstan and Uzbekistan). But since the late tenth century they had risen to become the dominant power in the Islamic world, conquering their way out of central Asia into Persia, taking control of Baghdad in 1055 with the approval of the Abbasid caliph, and subsequently branching out toward Syria, Armenia, Georgia, and the eastern fringes of Byzantium.
