Etchmiadzin Cathedral is the mother church of the Armenian Apostolic Church. Widely accepted as the oldest cathedral in the world, Etchmiadzin Cathedral was built in 301 AD by Saint Gregory the Illuminator following the adoption of Christianity as the state religion by King Tiridates III. It has served as the seat of the Catholicosate, the spiritual leader of all Armenians.

Rebuilt in 483 by Vahan Mamikonian after it was heavily damaged by a Persian invasion. Improvements to the cathedral were made in the 17th century by adding belfries. In 1868, a sacristy was added to the cathedral. Between 1955-1959 there were archaeological excavations and the cathedral went under major renovations.