The opposing armies represented different military philosophies, which derived from the nature of their societies. Arab armies contained sizeable contingents of both light and heavy cavalry, but relied primarily on their infantry, to the extent that the Arab cavalry was often limited to skirmishing during the initial phases of a battle, before dismounting and fighting on foot. While the Khazars had adopted elements of the civilizations of the south and possessed towns, they remained a largely tribal and semi-nomadic power. Like other steppe societies originating in Central Asia, they practiced a very mobile form of warfare, relying on highly skilled and hardy cavalry. As the historian Khalid Yahya Blankinship writes, "the Khazars were to prove difficult opponents for the Muslims, perhaps partly because their state was not highly organized and thus did not have a center whose fall would bring about a sudden collapse and rapid surrender".