Nestorianism was a denomination of Christianity which emphasized the distinction between the divine and human natures of Jesus. It originated with Nestorius, the Ecumenical Patriarch of Constantinople from 428 to 431 AD, who rejected Mary's title of "Mother of God". The Council of Chalcedon in 451 AD led to the Nestorian schism from the Christian Church, and many of Nestorius' supporters moved to Sassanid Persia, where they formed the Church of the East. The church was weakened by the Mongol conqueror Timur, who annihilated the church in Central Asia during the 1370s. In 1552, the Church of the East underwent a schism between a faction which entered into communion with the Catholic Church and another faction which became the Assyrian Church of the East.