Amadeus VIII of Savoy was born at Chambery in 1383 and died at Geneva in 1451. He was the son of Amadeus VII, whom he succeeded as count of Savoy in 1391. He was created duke of Savoy in 1416. In 1434, deeply affected by the deaths of his wife (1422) and eldest son (1431), he withdrew to the chateau of Ripaille, where he founded and governed an order of knights-hermits of St. Maurice. After the deposition of Eugene IV at the Council of Basel in 1439, Amadeus VIII was elected in his place. Since the election was carried out by one cardinal and thirty-two electors nominated by a commission, it was considered irregular. Since Amadeus was a deeply spiritual person he accepted this election with reservations. He abdicated as duke on January 6, 1440, and after ordination and consecration was crowned as Felix V at Basel on June 24 of that year.
He failed to receive the support of those who had elected him and ultimately found the position burdensome. After reaching an accomodation with the legitimately elected pope, Nicholas V, Amadeus solemnly abdicated in 1449 as the last of the antipopes. Nicholas appointed him cardinal bishop of Santa Sabina with a substantial pension.
From the description of Bollario di Felice V, 1440-1448(copies). (University of Michigan). WorldCat record id: 145567727