Martyr (c.314-335), thirty-ninth Bishop of Jerusalem. He opposed Arius and his new heresy, and at the Council of Nicæa assisted in formulating the Nicene Creed. The Emperor Constantine placed him in charge of the excavations for discovering the sites of the Passion and Resurrection and the finding of the True Cross. Under his supervision the church of the Holy Sepulcher was built. Feast, March 10,.