DUC, JOSEPH-AUGUSTE-MELCHIOR. - Bishop and historian, born in Châtillon (Aosta) on 18 February 1835, died in Aosta on 13 December 1922. Ordained priest on 18 December 1857, he was bishop of Aosta (22 July 1872–December 1907) and subsequently titular archbishop of Traianopoli (19 December 1907). He gave strong impetus to Catholic Action works, held eight synods, and established the minor seminary of S. Anselmo, opened on 27 October 1890.
He published 215 pastoral letters, notable for their breadth of treatment and doctrinal solidity, and around fifty works on the ecclesiastical history of the Aosta diocese, drawing extensively from unpublished material collected by Canon Antonio Gal. Special mention is deserved by: Cartulaire de l'évêché d'Aoste (XIIIe siècle), in Miscellanea di storia italiana, published by the R. dep. di st. patria di Torino, XXIII, Turin 1884, pp. 185-340; Documents sur l'histoire ecclésiastique du moyen âge, ibid., XXIV, ibid. 1885, pp. 335-69.
A. LONGNON, in Revue critique d'histoire et de littérature, 1885, pp. 417-418; G. MORIS, L'épiscopat valdôtain, Aosta 1923, pp. 161-168; P. VIAN, Dizionario biografico degli Italiani, XL, Rome 1991, pp. 749-751.