The original church was built in the early fourth century—between 301 and 303 according to tradition—by Armenia's patron saint Gregory the Illuminator, following the adoption of Christianity as a state religion by King Tiridates III. It was built over a pagan temple, symbolizing the conversion from paganism to Christianity. The core of the current building was built in 483/4 by Vahan Mamikonian after the cathedral was severely damaged in a Persian invasion. From its foundation until the second half of the fifth century, Etchmiadzin was the seat of the Catholicos, the supreme head of the Armenian Church.