 In 1752 he succeeded Bishop Joseph Butler as Clerk of the Closet, and in 1757 the archiepiscopate of York, to which the office of Lord High Almoner was added, crowned his long series of ecclesiastical preferments.Gilbert was mostly a place-holder archbishop.His health had begun to deteriorate prior to his appointment and he lived "through a pontificate of four years, when he sank under a complication of infirmities."