Pope from 537. In the Three Chapters Controversy he at first refused his assent to Justinian's condemnation of the writings of Theodore of Mopsuestia, Theodoret, and Ibas of Edessa. After he had been brought to Constantinople, he repudiated the Three Chapters in his ‘Iudicatum’ of 548, though not without reservations in favour of the Council of Chalcedon. His capitulation met with great opposition in the W. and the Pope retracted the ‘Iudicatum’. In 553 he refused to preside at the Second Council of Constantinople, but after the Council had condemned the Three Chapters, he eventually accepted its decision. The case was cited at the First Vatican Council by opponents of Papal infallibility.