Vincent of Lérins (died 445) entered the Cistercian monastery known as Lérins Abbey on Île Saint-Honorat, where under the pseudonym Peregrinus he wrote the Commonitorium, around 434, about three years after the Council of Ephesus.  Vincent defended calling Mary, mother of Jesus, Theotokos (God-bearer) in direct opposition to the Nestorian Heresy, which were the teachings of Patriarch Nestorius of Constantinople.  The Nestorian Heresy had previously been condemned by the Council of Ephesus.