Adelaide of Susa (also Adelheid, Adelais, or Adeline; c. 1014/1020 – 19 December 1091) was the countess of part of the March of Ivrea and the Marchioness of Turin in Northwestern Italy from 1034 to her death. She was the last of the Arduinici. She is sometimes compared to her second cousin and close contemporary, Matilda of Tuscany.
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.
Otto (French: Odon, Oddon, Othon; Italian: Oddone; c. 1023 – 1057/1060) was count of Savoy from around 1051 until his death. Through marriage to Adelaide, the heiress of Ulric Manfred II, he also administered the march of Susa from around 1046 until his death.