Ursicinus antipope, was a deacon of Rome, and claimed the election as successor of Tiberius over Damasus (q.v.), who was elected (A.D. 366) by a larger party of the clergy and the Roman people, and was recognized by the emperor Valentinian I, After a protracted conflict, Ursicinus was driven out of Italy, and went to Cologne. He returned to Italy in 381, and renewed the agitation, but was finally banished by the Council of Aquileia. He is not included in the lists of popes. See Herzog, Real-Encyklop. s.v.