the 8th century, Islam began to penetrate the region, the desert nomads of Arabia could militarily match the nomads of the steppe, and the early Arab Empire gained control over parts of Central Asia. The early conquests under Qutayba ibn Muslim (705–715) were soon reversed by a combination of native uprisings and invasion by the Turgesh, but the collapse of the Turgesh khaganate after 738 opened the way for the re-imposition of Muslim authority under Nasr ibn Sayyar. The Arab invasion also saw Chinese influence expelled from western Central Asia. At the Battle of Talas in 751 an Arab army decisively defeated a Tang dynasty force, and for the next several centuries Middle Eastern influences would dominate the region. Large-scale Islamization however did not begin until the 9th century, running parallel with the fragmentation of Abbasid political authority and the emergence of local Iranian and Turkic dynasties like the Samanids. Steppe empires Over time, as new technologies were introduced, the nomadic horsemen grew in power. The Scythians developed the saddle, and by the time of the Alans the use of the stirrup had begun. Horses continued to grow larger and sturdier so that chariots were no longer needed as the horses could carry men with ease. This greatly increased the mobility of the nomads; it also freed their hands, allowing them to use the bow from horseback. Using small but powerful composite bows, the steppe people gradually became the most powerful military force in the world. From a young age, almost the entire male population was trained in riding and archery, both of which were necessary skills for survival on the steppe. By adulthood, these activities were second nature. These mounted archers were more mobile than any other force at the time, being able to travel forty miles per day with ease. The steppe peoples quickly came to dominate Central Asia, forcing the scattered city states and kingdoms to pay them tribute or face annihilation. The martial ability of the steppe peoples was limited, however, by the lack of political structure within the tribes. Confederations of various groups would sometimes form under a ruler known as a khan. When large numbers of nomads acted in unison they could be devastating, as when the Huns arrived in Western Europe. However, tradition dictated that any dominion conquered in such wars should be divided among all of the khan's sons, so these empires