On 26 May 451, the armies of the Sassanid Empire defeated the forces of Saint Vartan Mamigonian and the Armenians at the Battle of Avarayr. This day is considered one of the most important dates for the Armenian people.
On the fields of Avarayr, 66,000 Armenians faced off against 220,000 Sassanids. The Armenians were led by Saint Vartan, who died in the battle. Although the Armenians were defeated, the Sassanids experienced such heavy losses in the battle that continuing Armenian resistance would eventually lead to the granting of religious freedom in 484.
Moreover, since the Armenians were occupied with their struggles against the Sassanids, they were unable to send delegates to the Council of Chalcedon which would define the dyophysite [or dual] nature of Christ as true God and true Man. The Armenians would reject this council and its status as ecumenical and instead proclaim a miaphysitism which defined Christ has having only one nature in which the divinity and humanity of Christ are joined without confusion or alteration.
Today, the Armenian Orthodox Church remains separate both from the Catholic and the Eastern Orthodox Churches. Though there is an Armenian Catholic Church in communion with the Holy See.
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