The tribe was the main solidarity group in Transjordan on the eve of the establishment of the modern state in 1921. As in many tribal societies in the Middle East, the creation of the state system in the aftermath of World War I brought about dramatic changes in the lives of tribespeople, and nomads in particular. The emergence of colonial governments with centralizing ambitions; the creation of international borders; rapid economic changes; and the spread of national ideologies were among the factors that threatened the survival of old tribal order and indeed put enormous pressures on tribespeople everywhere. Nevertheless, in the case of Transjordan, twenty-five years after the process of state-formation and modernization had been launched, tribal identities had not disappeared. Rather, tribes remained important social and cultural categories, having adapted to new realities and transformed in the face of them. Moreover, in the course of this process, the tribal population of Transjordan became the backbone of the Hashemite regime and among the most enthusiastic supporters of the kingdom. Even today, tribal identities, though significantly modified since the days of the Mandate, continue to play a major role in Jordanian politics. Scholars of modern Jordan have acknowledged the special relations between the tribes and the Hashemite monarchy. They have also emphasized the centrality of tribes and tribal political culture in contemporary Jordan. The historical roots of these phenomena, however, deserve further exploration.