The Challant were a Valdostan noble family, appeared in the twelfth century and enjoyed great power during the Middle Ages and the Renaissance, period during which they ruled much of the Valle d'Aosta on behalf of the Savoy.
Throughout history, members of the Challant family have given birth to several cadet branches (Challant-Aymavilles, Challant-Châtillon, Challant-Cly, Challant-Ussel and Saint-Marcel, Challant-Fénis, Challant-Varey in France) and have occupied in Valle d'Aosta different positions of both temporal and spiritual importance.
It is generally considered a progenitor of the Bosone I family, mentioned in a document of 1100 as Visconte di Aosta, a title reserved for the administrator of the County of Aosta on behalf of the Savoy.
However, the name Challant is used for the first time by Bosone II, nephew of Bosone I, after having received from the Savoy the castle of Villa and the Lordship of Challant, in today's Val d'Ayas.
The family died out in 1804 with the death of Filippo Maurizio (n.1724), the last male descendant of Casa Challant. In 1802 Giulio Giacinto, great-grandson of Filippo Maurizio, died at the age of 7. In 1837 Teresa, the last woman of the family, died and with her the Challant dynasty ended.