Italian pope (1792–1878), born Giovanni Maria Mastai-Ferretti, who ascended the papal throne in 1846 and served until his death. Among the notable achievements of his 32-year reign, the longest in Church history, Pius convened the historic First Vatican Council, which included the doctrine of papal infallibility. Untranslated letter to Don Carlos, Infante of Spain, and the leader of the Carlists, written during the third Carlist War. In fine condition, with intersecting folds, one through first letter of signature, some scattered light toning and creasing, and a couple small pencil notations. RRAuction COA.
