The Social Consequences of Migration of Arab tribes toward Khorasan in the First Islamic Centuries

Arabs migrated towards Iran in numerous ears and due to different reasons. Before Islam، famine، drought، poverty، the breach of Ma’areb dam as well as Al-Qaram flood; moreover، the religious and economic motivations were considered the most effective elements of migrations after Islam. The geographical situation، economic advantages besides being faraway from the center of caliphate، Khorasan was regarded the main purposes of migrators. The social consequences of these migrations were the development of cities، the change in the structure of social classes، the advent of governors، as well as the enhancement of tribal disagreements among migrated Arabs which have been thoroughly investigated in this article.