St. Cyril, Bishop of Alexandria, fought with his pen and his eloquence against the Nestorians.  He presided in the name of Pope Celestine at the great Council of Ephesus, where the heresy of Nestorius was condemned, and he successfully defended the truth concerning the Mother of God and our Savior in His twofold nature of God and Man.  He died A.D. 444.

Also: Commemoration of St. Apollonia, Virgin, Martyr

St. Apollonia, Virgin of Alexandria, after having her teeth broken, cast herself into the flames prepared for her, under the emporer Decius, A.D. 259.

Proper on p. 1180, 1032, 1048.  Common Preface on p. 886.