According to the Catholic Encyclopedia entry on this saint:
Bishop of Jerusalem and Doctor of the Church, born about 315; died probably 18 March, 386. In the East his feast is observed on the 18th of March, in the West on the 18th or 20th. Little is known of his life. We gather information concerning him from his younger contemporaries, Epiphanius, Jerome, and Rufinus, as well as from the fifth-century historians, Socrates, Sozomen and Theodoret. Cyril himself gives us the date of his "Catecheses" as fully seventy years after the Emperor Probus, that is about 347, if he is exact.
St. Cyril is one of the Church Fathers I quote in Return to Rome. Here is St. Cyril, from his Catechetical Lectures ("Catecheses"), on the nature of the Eucharist:
2. He once in Cana of Galilee, turned the water into wine, akin to blood, and is it incredible that He should have turned wine into blood? When called to a bodily marriage, He miraculously wrought that wonderful work; and on the children of the bride-chamber [Matthew 9:15], shall He not much rather be acknowledged to have bestowed the fruition of His Body and Blood?
3. Wherefore with full assurance let us partake as of the Body and Blood of Christ: for in the figure of Bread is given to you His Body, and in the figure of Wine His Blood; that you by partaking of the Body and Blood of Christ, may be made of the same body and the same blood with Him. For thus we come to bear Christ in us, because His Body and Blood are distributed through our members; thus it is that, according to the blessed Peter, we become partakers of the divine nature [2 Peter 1:4].