The Battle of Nineveh was the climactic battle of the last of the wars between the Eastern Roman Empire and the Sassanid Persian Empire, in 627. The Byzantine victory broke the power of the Sassanidss and briefly restored the Empire to its ancient boundaries in the Middle East.
During a six-year campaign, the Byzantine Emperor Heraclius had driven the Persians from Asia Minor back into their own territories, but the Persian Kasrā Khosrau II still refused to make peace. On December 12, 627, the main armies of Heraclius, in personal command, and Khosrau's army commanded by the general Rhahzadh, met at Nineveh. As many as 100,000 soldiers may have been engaged in the battle.
The battle was closely contested, but Heraclius' superior generalship won the day, and Rhahzadh was killed in the fighting. Finally, the Persian army was driven from the field and Persia lay open to the Byzantine army. The next year, Heraclius captured the Persian capital of Ctesiphon and Persia accepted Heraclius' peace terms.