Today is the memorial of St Cyril of Jerusalem, Bishop and Doctor of the Church.
The breviary note says about him:
Born of Christian parents in the year 315. He succeeded Maximus as Bishop of Jerusalem in 348. He was involved in the Arian controversy and more than once was sentenced to exile. His Catecheses in which he explained the true doctrine of the faith and Sacred Scripture as well as the tradition of the Church for the sake of the people show his pastoral zeal. He died in the year 386.
His Catholic Encyclopedia entry is here.