LIBERIUS, CASE OF POPE. In the midst of the Arian crisis Pope Liberius was banished by the Arian Emperor Constantius II in A.D. 355 for refusing to condemn St. Athanasius. Two years later he is alleged to have signed an Arian formula of faith to regain his freedom. Certain documents discrediting him are forgeries. In any event, it is certain that he signed no document freely, and so papal infallibility is not involved.