Khuzestan Central Persia Caucasus Pars Khorasan Other geographies Ridda Wars Conquest of Sasanian Persia Conquest of Byzantine Syria Campaigns in Africa Campaigns in Armenia and Anatolia The Battle of the River, also known as Battle of Al Madhar, took place in Mesopotamia (Asoristan Province) between the forces of the Rashidun Caliphate and the Sasanian Empire.

Survivors from the Battle of Chains had informed commanding officers of how Persian veterans had abandoned them and joined the Muslim forces allowing the Muslims to fill up their lines with experienced Persian veterans who converted to Islam and would face inexperienced conscripts, the idea would lead many to abandon the cause and return home.

Karinz chose this place because it was near the Euphrates River making it easier for the Persian regulars to arrive with ease.

The aim was to arrive before the Persian forces could gather their strength and strike them whilst weak and unprepared, like most battles this tactic would allow Khalid to exploit and execute many maneuvers before experienced armies could react.

Persian army was deployed with the river close behind to it with fleets of boats ready at the near bank to facilitate withdrawal.

[3] The Persian army here now lost all the top generals, yet the men fought bravely and were able to hold the Muslim attacks for a while.

Eventually, under the continued Muslim attacks, the Persian army lost all cohesion, turned about and made for river bank.

Abu Bakr didn't direct Khalid to move deeper into the Sassanid territory, and after nine months he sent him to command the invasion of Byzantine Empire on the Syrian front.