Cyril of Alexandria

Saint Cyril of Alexandria was one of the most important theologians and Church Fathers of the 5th century. Nephew of Theophilus, he succeeded him as Patriarch of Alexandria in 412. His episcopate was marked by major theological controversies, notably the struggle against Nestorianism. He presided over the Council of Ephesus in 431, where he fervently defended the doctrine of the Incarnation, affirming the hypostatic union of Christ and the divine motherhood of Mary (Theotokos). His writings profoundly influenced Christology and Mariology, and he is recognized as a Doctor of the Church.