Elected by the supporters of the former Pope Liberius (352-366), against the majority pick of Pope Damasus I (366-383). A year long blood feud between the two popes ending with Ursinus being banished to Cologne by Emperor Valentinian I in 367.
Rulers & Events:
352-366: Pope Liberius
364-375: Western Roman Emperor, Valentinian I
364-378: Eastern Roman Emperor, Valens
366-383: Pope Damasus I
367-369: The Great Conspiracy, rebellion in Roman Britan