Duke of Aosta in the context of "County of Aosta"

Victor Amadeus II (Italian: Vittorio Amedeo Francesco, Arpitan: Victor-Amèdê, French: Victor-Amédée; 14 May 1666 – 31 October 1732) was the head of the House of Savoy and ruler of the Savoyard states from 12 June 1675 until his abdication in 1730. He was the first of his house to acquire a royal crown, ruling first as King of Sicily (1713–1720) and then as King of Sardinia (1720–1730). Among his other titles were Duke of Savoy, Duke of Montferrat, Prince of Piedmont, Marquis of Saluzzo and Duke of Aosta, Maurienne and Nice.

Louis XIV arranged his marriage in order to maintain French influence in Savoy, but Victor Amadeus soon broke away from the influence of France. At his father's death in 1675, his mother, Marie Jeanne Baptiste of Nemours, was regent in the name of her nine-year-old son and would remain in de facto power until 1684 when Victor Amadeus banished her further involvement in the state. Having fought in the War of the Spanish Succession, he was rewarded with the Kingdom of Sicily in 1713, but he was forced to exchange this title for the poorer Kingdom of Sardinia in 1720.

The Duchy of Aosta, originally the County of Aosta (French: Duché d'Aoste), was a realm ruled by the House of Savoy from the early 11th century until the late 18th, when its independent institutions were aligned with those of the Principality of Piedmont. The title "Duke of Aosta" continued to be used by the second sons of the Savoyard monarch. The land of the duchy is today a part of Italy.

The county of Aosta was originally ruled by the bishops of Aosta in the 10th and early 11th centuries. Upon the death of Bishop Anselm in 1026, however, Conrad the Salic ensured that the secular powers of the important Alpine territory passed to the bishop's brother-in-law, his ally Humbert the White-handed, rather than remaining tied to the diocese, which fell to Anselm's unfriendly nephew Burchard. Humbert's son Odo then wed Adelaide, securing the March of Turin. The county was elevated to a duchy by Frederick Barbarossa.