In 484, at the Syond of Beth Lapat, the Assyrian Church of the East under the leadership of the Catholicos Bar Sauma declared the teaching of Nestorius the official doctrine, and also decided that all monks church dignitaries should marry.

The adoption of Nestorius' teaching, who had been condemned in Ephesus in 431, effectively separated the Assyrian Church from the Byzantine church.

The decisions were clearly aimed at pleasing the Zoroastrian Persian kings, who were at constant war with the now Christian Byzantine Empire: the previous pro-Byzantine Catholicos Babowai had been executed, and the Persians had given protection to Nestorian refugees since 462. As Zoroastrians, they viewed family life sacred and abhorred the monastic movement of the Christians.

The decision did not improve the Persian state policy against the church. Instead, it severely weakened its spiritual life. Some members of the church even left and joined the new Monophysite Church. Already at the episcopal gathering of 544 some of the decisions were reverted.