Amadeus had been in close relations with the Council of Basel-Ferrara-Florence and was elected at Basel as Pope Felix V, in opposition to Pope Eugene IV. The Cardinal of Arles reminded the Council that they needed a rich and powerful pope to defend it from its adversaries. After long negotiations with a deputation from the council, Amadeus acquiesced in the election, 5 February 1440, completely renouncing at the same time all further participation in the government of his duchy. He named his son Louis, Duke of Savoy, and Philip, Count of Geneva. He reigned from November 1439 to April 1449. His supporters came from the movement to have the Church managed by Ecumenical councils, and prelates like Cardinal Aleman, who wanted to set limits upon the doctrine of Papal supremacy.