After the Battle of Jalula, peace was concluded with the Persians and there was no fighting for a few months. But the Persians soon broke the treaty and Muslims were compelled to fight them again.
The Persian Emperor led an army of sixty thousand while the Muslims were 30,000 in number. The two armies met at Nahawand. For two days, they fought without a clear gain to either side. On the third day, Persians took refuge in their forts. The Muslims did not want to prolong the fighting so by a clever strategy, the enemy was forced to come out into the open.
Hand to hand fighting took place. Persians were defeated and their power was completely shattered. Yazdgard, the Persian King, fled to Isfahan, then to Kirmah and from there to Balkh where he was killed during the Khilafat of Hazrat Usman.
This battle was one of the decisive wars of history that sealed the fate of the Persian Empire and paved the way for the Muslims to rise as a world power. It proved to be a gateway to Persia. This was the last great battle of fought between the Persian and the Muslim.