The tribes were a powerful social and political factor throughout Iranian history. The skills necessary for herding animals, hunting and chasing off predators, directing migrations, disciplining tribesmen, and protecting lands and animals from rivals could be easily adapted and directed toward military purposes as well. It was typically the tribes that produced the soldiers and rulers of the country and provided the power base for most of its dynasties. Once established, governments needed to cultivate the support of friendly tribal groups and tried to control hostile tribes by combat, deportation, or forcible settlement. At the beginning of the twentieth century, approximately one-fourth of the population were tribal peoples, and they were a potent force in Iranian affairs. With the advent of mechanized armies in the 1930s, however, there were systematic efforts to break the power of the tribes and to coerce the tribal population into a sedentary way of life. These efforts have been largely successful, and the tribes are no longer so significant a force in either the Iranian economy or society. Less than 5 percent of the population now consists of nomadic pastoralists.
