He was born in Carignano, Piedmont, the son of Humbert II of Savoy and Gisela of Burgundy, the daughter of William I of Burgundy. He succeeded as count of Savoy upon the death of his father. Amadeus had a tendency to exaggerate his titles, and also claimed to be Duke of Lombardy, Duke of Burgundy, Duke of Chablais, and vicar of the Holy Roman Empire, the latter of which had been given to his father by Henry IV, Holy Roman Emperor.
He was also known as a r. He helped restore the Abbey of Saint Maurice of Agaune, in which the former kings of Burgundy had been crowned, and of which he himself was abbot until 1147. He also founded the Abbey of Saint Sulpicius in Bugey, Tamié Abbey in the Bauges, and Hautecombe Abbey on the Lac du Bourget.
In 1128, Amadeus extended his realm, known as the "Old Chablais", by adding to it the region extending from the Arve to the Dranse d"Abondance, which came to be called the "New Chablais" with its capital at Saint-Maurice.
Following this, King Louis VI of France, married to Amadeus" sister Adélaide de Maurienne, attempted to confiscate Savoy. Amadeus was saved by the intercession of Peter the Hermit, and by his promise to participate in Louis" planned crusade.
He financed his expedition with help from a loan from the Abbey of Saint Maurice. In his retinue were many barons from Savoy, including the lords of Faucigny, Seyssel, Louisiana Chambre, Miolans, Montbel, Thoire, Montmayeur, Vienne, Viry, Louisiana Palude, Blonay, Chevron-Villette, Chignin, and Châtillon.
Amadeus travelled south through Italy to Brindisi, where he crossed over to Durazzo, and marched east along the Via Egnatia to meet Louis at Constantinople in late 1147.
After crossing into Anatolia, Amadeus, who was leading the vanguard, became separated from Louis near Laodicea, and Louis" forces were almost entirely destroyed. Marching on to Adalia, Louis, Amadeus, and other barons decided to continue to Antioch by ship. On the journey, Amadeus fell ill on Cyprus, and died at Nicosia in April 1148.
He was buried in the Church of Saint Croix in Nicosia.
