He helped restore the Abbey of St. Maurice of Agaune, in which the former kings of Burgundy had been crowned, and of which he himself was abbot until 1147.

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.

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.

In Savoy, his son Humbert III succeeded him, under the regency of bishop Amadeus of Lausanne.