“ DURAND, GUILLAUME (Guillelmus Durandus) , also known as Duranti or Durantis, from the Italian form of Durandi filius, as he sometimes signed himself (c. 1230–1296) , French canonist and liturgical writer, and bishop of Mende, was born at Puimisson, near Beziers, of a noble family of Languedoc. He studied law at Bologna, especially with Bernardus of Parma, and about 1264 was teaching canon law with success at Modena. ”

“ Fano, 1569) , of especial value owing to the share of Durandus in the elaboration of the constitutions of this council (1274) , and inserted by Boniface VIII. in the Sextus.
A nephew of “The Speculator,” also named Guillaume Durand (d. 1330) , and also a canonist, was rector of the university of Toulouse and succeeded his uncle as bishop of Mende. He wrote in 1311, in connexion with the council of Vienne, De modo celebrandi concilii et corruptelis in Ecclesia reformandis. It attacks the abuses of the Church with extreme sincerity and vigour. ”

“ In the midst of the struggles between Guelfs and Ghibellines, Durandus successfully defended the papal territories, both by diplomacy and by arms. Honorius IV. retained him in his offices, and although elected bishop of Mende in 1286, he remained in Italy until 1291. ”