The successful Siege of Ctesiphon (, also known as 'Al-Mada'in المدائن in Arabic) by the Rashidun army lasted about two months, from January to March 637. Ctesiphon, located on the east bank of the Tigris, was one of the great cities of the Persian Empire, an imperial capital of the Arsacids and of their successors, the Sassanids. Soon after the conquest of the city by Muslims, Sassanid rule in Iraq ended.