pope, was born in Rome about the year 270, and was the son of Rufinus and St. Justa. At thirty years of age he is said to have been ordained by bishop (pope) Marcellinus, and on Jan. 31, 314, he was chosen to succeed Melchides in the pontificate. His administration is celebrated for the Council of Niceea (q.v.), held in 325, which, however, Sylvester did not attend, on account of his infirmities; and he was represented by two priests, called Guy and Vincent, while Osiis, bishop of Cordova, presided in his name. He is the author of several rules to the clergy. The account given of the donation to him of the city of Rome by Conatantine is wholly apocryphal. He died in Rome, Dec. 31, 335, and was succeeded by Marcus.