States in Iran were formed from complex processes. Iranian dynasties from attacking of Saljuqs until Reza Shah in the 1920s were tribal in origin except the Safavids. State rulers were themselves originally tribal leaders or their descendants.
Tribes ...

States in Iran were formed from complex processes. Iranian dynasties from attacking of Saljuqs until Reza Shah in the 1920s were tribal in origin except the Safavids. State rulers were themselves originally tribal leaders or their descendants.
Tribes in Iran were formed out of the intersection of dependence on resources, external powers and pressures. Tribes and states in Iran through history were interdependent and maintained each other as a single system. State rulers especially depended on tribes for military power, revenue, and regional system. They found it useful to consider a group of people to be a tribe. Tribal leaders in Iran emerged from local, regional, and governmental relationship. In the nineteenth and early twentieth centuries tribal combinations were Iran's largest and effective organized political groups. State rulers in Iran often had to share power with tribes. During the constitutional revolution in 1906-1911, tribal groups were major powers in the struggle over the Qajar state. Tribal groups and leaders were variously allied with and internal tribal and confederational struggle often mirrored the wider conflicts.
Many states in Iran began as tribal dynasties societies emerged confederacies, empires, and states. Tribal groups in Iranian history have ranged from small, loosely organized, noncentralized groups to fragmented and ephemeral tribal confederacies with centralized, hierarchical leadership systems. Tribes in Iran were a constant in that they offered a continual reservoir of military force.