Turkey has been inhabited since the paleolithic age, including various ancient Anatolian civilizations, Aeolian, Dorian and Ionian Greeks, Thracians, Armenians, and Assyrians. After Alexander the Great's conquest, the area was Hellenized, a process which continued under the Roman Empire and its transition into the Byzantine Empire. The Seljuk Turks began migrating into the area in the 11th century, starting the process of Turkification, which was greatly accelerated by the Seljuk victory over the Byzantines at the Battle of Manzikert in 1071. The Seljuk Sultanate of Rûm ruled Anatolia until the Mongol invasion in 1243, upon which it disintegrated into several small Turkish beyliks.