The siege of Ctesiphon took place from January to March, 637 between the forces of Sassanid Empire and Rashidun Caliphate. Ctesiphon, located on the eastern bank of the Tigris, was one of the great cities of Persia, the imperial capital of the Parthian and Sassanid Empires. The Muslims managed to capture Ctesiphon ending the Persian rule over Mesopotamia.