Iranian events of 1921

1921 Persian Coup
Date 21 February 1921 Location Tehran Result Persian Cossack Brigade victory power takeover by Sayyed Ziaoddin Tabatabaee suppression of Colonel Pessian's revolt and dissolution of the Autonomous Government of Khorasan dissolution of the Republic of Gilan continuing conflict with Simko Shikak until 1922 deterioration of Persian control over Sheikh Khazal's Emirate of Mohammerah until 1925
Government-Insurgents
Government of Persia	Persian Cossack Brigade Supported by: United Kingdom
Commanders and leaders
Fathollah Khan Akbar	Rezā Khan Mirpanj Zia'eddin Tabatabaee Ahmad Amir-Ahmadi Edmund Ironside
Strength
	1,500 Persian Cossacks
Casualties and losses
several policemen killed or injured in Tehran during the coup

Persian Cossack Brigade victory

Persian Cossack Brigade

Rezā Khan Mirpanj
Zia'eddin Tabatabaee
Ahmad Amir-Ahmadi

1921 Persian coup d'état, known in Iran as 3 Esfand coup d'état (Persian: کودتای ۳ اسفند ۱۲۹۹‎‎), refers to several major events in Persia (Iran) in 1921, which eventually led to the establishment of the Pahlavi dynasty as the ruling house of the country in 1925.

The events began with a coup led by leaders of the Persian Cossack Brigade such as Colonel Mohammad Taghi Pessian, and directed by the British, on 21 February 1921. With this coup the British established Rezā Khan as the most powerful person in Iran. The coup was largely bloodless and faced little resistance. With his expanded forces and the Cossack Brigade, Colonel Mohammad Taghi Pessian and several other generals launched successful military actions to eliminate separatist and dissident movements in Tabriz, Mashhad and the Janglis in Gilan. The campaign against Simko and the Kurds was less successful and lasted well into 1922, though eventually concluding with Persian success.

...
Wikipedia