Nestorianism is a Christological doctrine advanced by Nestorius; Patriarch of Constantinople from 428-431. Nestorius and his teachings were eventually condemned as heretical at the First Council of Ephesus in 431 and the Council of Chalcedon in 451; leading to the Nestorian Schism in which churches supporting Nestorius broke with the rest of the Christian Church.

Afterward many of Nestorius' supporters relocated to Sassanid Persia; where they affiliated with the local Christian community; known as the Church of the East. Subsequently the Church of the East became increasingly Nestorian in doctrine; leading it to be known alternately as the Nestorian Church. Pictures From History