The ancient custom in Wales, as throughout Celtic Christendom, was to have bishops who were abbots of monasteries, and who had no clear territorial jurisdiction, simply traveling about as they were needed. Eventually, however, the bishops of Bangor, Llandaff, St. Asaph, and St. Davids became the heads of four territorial dioceses, to which the diocese of Monmouth and the diocese of Swansea and Brecon have been added in this century.
For many centuries the Church in Wales had closer ties with the Celtic Churches in Scotland, Ireland, and Brittany than with the Church in Anglo-Saxon England. However, after the Norman conquest of Britain (1066 and after), the Anglo-Norman Kings began to contemplate the conquest of Wales. William the Conqueror began with the subjugation of South Wales as far as Carmathen, but the Welsh uplands remained independent far longer, and the conquest was not complete until about 1300, under Edward I. But eventually all of Wales came under English control, and the Church in Wales was placed under the jurisdiction of Canterbury, and thus became identified in the minds of many with the English supremacy. In 1920 the Church in Wales (Eglwys yng Nghymru) became independent of outside jurisdiction (though still in communion with other Anglican Churches, in England and elsewhere) and clear of all ties with the government. It is bilingual and active in the preservation of the Welsh language and culture.