In 1946 and 1948, James Conway Davies published volumes one and two of his Episcopal Acts and Cognate Documents Relating to Welsh Dioceses 1066-1272. These volumes included over 400 pages of introduction (on such topics as sources, the Norman conquest and its impact on the church in Wales, the formation of the bishoprics, diocesan boundaries, the status of St Davids, the structure of the church, etc.) and in calendar form the acts of the dioceses of St Davids and Llandaff. A notice in the front of volume two indicates that volume three would have contained inter alia the acts of the dioceses of Bangor and St Asaph and an index of the acts contained in all three volumes. Volume three was promised for publication in 1950/1, but for some reason never saw the light of day. The editor left behind a massive card index and the galley proofs of the acts of St Asaph and Bangor and it is these that form the basis of the present volume. It therefore completes what is both a monumental study on and source of information for the Church in medieval Wales.