He is also called the White-Handed (Italian: Umberto Biancamano; French: Humbert Blanches-Mains) reportedly to signify his generosity, however, this retroactively applied title may derive from a textual mistranslation of an early Latin record which actually refers to the walls of his castle, not his hands, as white.[1].
During the wars between Rudolph III of Burgundy and the Emperor Henry II, Humbert supported the latter with provisions and soldiers, for he was related to the imperial family by marriage. Thus, in 1003, the emperor installed him as the Count of Aosta, a mountainous region then a part of Burgundy but today within Italy, and granted him the northern Viennois as a reward. Humbert in turn protected the right flank of Henry's army during his subsequent invasion of Italy (1004).
Humbert's lands were essentially autonomous after the death of Henry. Their inaccessibility and their minor importance lent them to being overlooked and ignored in the power struggles which inevitably followed the death of the emperor. In 1032, Humbert received the Maurienne, his native country, from the Emperor Conrad II, whom he had helped in his Italian campaigns against Aribert, Archbishop of Milan.