 Two notable learned men, Juan de Segovia and Alfonso Tostado de Madrigal, were affiliated with the University of Salamanca in the fifteenth century. A short account of their careers will highlight the range of views that characterized Spanish theology at the university in those years. Juan, a professor of theology (1422–1435), participated in the Council of Basel (1431–1449), beginning in 1432. He defended conciliar supremacy and supported the doctrine of Mary’s immaculate conception. His writings include polemics on behalf of the council against Pope Eugenius IV (1431–1447) and a History of the General Council of Basel. Juan was made a cardinal by the antipope Felix V (1439–1449); but he retired after Felix yielded to Eugenius’ successor, Nicholas V (1447–1455). In retirement, Juan wrote on the need for dialogue with Islam. Aware of his impending death (c. 1458), Juan bequeathed his library to the university.