Descripción
The Battle of al-Qadisiyyah took place between the armies of the Rashidun Caliphate and the Sasanid Empire in November 636. It resulted in a decisive victory for the Rashidun army and is considered to be one of the most significant engagements on the Persian campaign, and thereby of the early caliphate expansion as a whole.
Both Sasanid & Rashidun are recovering from recent civil war and the Rashidun were forced to battle in two front against the Romans in Syria and Sasanid in Iraq.
After losing at Qadisiyyah, the Sasanian army was broken and unable to defend against the Rashidun siege of its capital at Ctesiphon, thus being forced to retreat from all of Mesopotamia. This development enabled further Rashidun offensives into the Persian mainland and culminated in the collapse of Sasanian Empire in 651.