The weak rule of the Persian Shah, the semiblind Soltan Mohammad, has allowed usurpation by the amirs, or chiefs, of the Turkmen tribes, who have brought the Safavids to power and still constitute the backbone of Safavid military strength.

Moreover, the intertribal factionalism of these Turkmens (known as Kizilbash [Red Heads] because of the distinctive red headgear that they have adopted to mark their adherence to the Safavids) has so weakened the state that its traditional enemies, the Ottoman Turks to the west and the Uzbeks to the east, have been able to make large inroads into Persian territory.