Cyril’s life began a few years before Arianism (the heresy that Jesus was not divine or one in being with the Father) and he lived to see its suppression and condemnation at the end of his life. In between he was the victim of many of the power struggles that took place. We know little about Cyril’s early life. Historians estimate he was born about 315 and that he was brought up in Jerusalem.
When Maximus died, Cyril was consecrated as bishop of Jerusalem. Because he was supported by the Arian bishop of Caesarea, Acacius, the orthodox criticized the appointment and the Arians thought they had a friend. Both factions were wrong, but Cyril wound up in the middle.
When a famine hit Jerusalem, the poor turned to Cyril for help. Cyril, seeing the poor starving to death and having no money, sold some of the goods of the churches. This was something that other saints including Ambrose and Augustine had done and it probably saved many lives. Eleven years later, Cyril was allowed to go back to find a Jerusalem destroyed by heresy and strife. He was never able to put things completely right. He did attend the Council at Constantinople in 381 where the Nicene Creed and orthodoxy triumphed and Arianism was finally condemned. Cyril received justice at the same Council who cleared him of all previous rumors and commended him for fighting “a good fight in various places against the Arians.” Cyril had eight years of peace in Jerusalem before he died in 386, at about seventy years old.