Complex rivalries in the region of Khorasan led to the Afghan Hotak dynasty invading Iran. In 1722, this conflict led to the collapse of the Safavid Empire after the siege of Isfahan. The brief interlude between 1722 and the rise of the Qajar dynasty in 1789–1796 was marked by widespread political turmoil in Iran and several rival attempts to establish power over the country. The Safavids failed to regain power and the Hotaks failed to establish control. The rival Afsharid and Zand dynasties were established by Nader Shah (1736–1747) and Karim Khan (1751–1779), respectively.