Prelude
Western Armenia had been under
Byzantine control since the partition of the
Kingdom of Armenia in AD 387, while Eastern Armenia had been under the occupation of the
Sassanid Empire starting 428. Regardless of religious disputes, many Armenians became successful in the Byzantine Empire and occupied key positions. In Sassanid-occupied Armenia, the people struggled to preserve their Christian religion. This struggle reached its culmination in the
Battle of Avarayr. Although the battle was a military defeat, Vartan Mamigonian's successor, Vahan, succeeded to force the Persians to grant religious freedom to the Christian Armenians in the Nvarsak Treaty of 484.