Aleman was born of a noble family at the castle of Arbent near Bugey. A relative was the Papal Chamberlain. He was successively bishop of Maguelonne (1418), archbishop of Arles (1423) and Cardinal Priest of S. Cecilia (1426), promoted by Pope Martin V.
Aleman was a prominent member of the Council of Basel, and, together with Cardinal Julian Cesarini, led the party which maintained the supremacy of general councils over the pope's authority. Aleman later led opposition to the pope, but Cesarini was reconciled with Pope Eugene IV, playing a prominent part in Eugenius' Council of Florence. In 1439 Aleman led the effort to depose of Pope Eugene IV and the election of a successor. In 1440, Aleman placed the tiara upon the head of Amadeus VIII, Duke of Savoy (henceforward known as Antipope Felix V). Eugenius responded by excommunicating the antipope and depriving Aleman of all his ecclesiastical dignities.
Aleman was involved in unsuccessful efforts to win over Europe's princes to Basel's pope Felix V. In order to make an end of the schism, Felix V finally abdicated on Aleman's advice; and Nicholas V, who had succeeded in 1447, restored the cardinal to all his honors and employed him as legate to Germany in 1449.
- Thurston, Herbert (1913). "Blessed Louis Allemand". In Herbermann, Charles. Catholic Encyclopedia. New York: Robert Appleton Company.
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Aleman, Louis". Encyclopædia Britannica. 1 (11th ed.). Cambridge University Press. p. 539.
- See U. Chevalier, Repert. des sources hist. (Paris, 1905), p. 130.