In dioceses of the fourth century and later, head of a college of presbyters as special representative of the bishop; also, in larger rural localities or in extensive dioceses in the West, head of the central mother-church or a diocesan subdivision or deanery. Union of several of either constituted an archidiaconate whose individual deans or archpriests were subject to the archdeacon. In time this office underwent varying local changes; since the Council of Trent the duties of archpriest have been largely assumed by deans.