Which two armies fought "The Battle of Avarayr"?

"The Battle of Avarayr" was fought on 2 June 451 on the Avarayr Plain in Vaspurakan between the Armenian Army under Vardan Mamikonian and Sassanid Persia. It is considered one of the first battles in defense of the Christian faith. Although the Persians were victorious on the battlefield, the battle proved to be a major strategic victory for Armenians, as Avarayr paved the way to the Nvarsak Treaty of 484 AD, which affirmed Armenia's right to practise Christianity freely.

The battle is seen as one of the most significant events in Armenian history. The commander of the Armenian forces, Vardan Mamikonian, is considered a national hero and has been canonized by the Armenian Apostolic Church.

Armenian resistance continued in the decades following the battle, led by Vardan's successor and nephew, Vahan Mamikonian. In 484 AD, Sahag Bedros I signed the Nvarsak Treaty, which guaranteed religious freedom to the Christian Armenians and granted a general amnesty with permission to construct new churches. Thus, the Armenians see the Battle of Avarayr as a moral victory; 2 June 451 is considered to be a holy day by Armenians and is one of the most important national and religious days in Armenia.