The Battle of Avarayr, also known as the Battle of Vartanantz, is fought on May 26, 451 on the Avarayr Plain in Vaspurakan, between the Armenian Army under Saint Vartan and their Sassanid rulers.

Although the Persians are victorious on the battlefield, they have heavy casualties and, following subsequent uprisings and guerilla warfare, the Armenians are eventually guaranteed religious freedom.