Pope Liberius served as the Bishop of Rome from 352 to 366 AD. He is known for his role during a time of significant theological conflict, particularly regarding the nature of Christ and the Arian controversy. Liberius initially opposed the Arian position but later faced pressure from the Roman Emperor Constantius II, which led to his temporary exile. During his papacy, Liberius was involved in the Council of Sirmium, which sought to address the Arian controversy. His leadership was marked by challenges, including the struggle to maintain orthodoxy within the Christian Church amidst political and theological pressures.