The English counties remained largely the same from the Middle Ages until 1974. The Church of England dioceses remained the same from the reign of Henry VIII to the 1830s. However, since the 1830s there have been very frequent changes as the Church has adapted to population growth and urbanization. The following dioceses have been created: Ripon 1836, Truro 1876, Liverpool 1880, Southwell 1884, Wakefield 1888, Birmingham 1905, Southwark 1905, Bury St Edmunds 1914, Chelmsford 1914, Sheffield 1914, Coventry 1918, Bradford 1919, Blackburn 1926, Derby 1927, Guildford 1927, Leicester 1927, Portsmouth 1927. This list was taken from a book about cathedrals. It does not provide information on the boundaries of the dioceses. There may have been changes of boundary apart from those associated with the establishment of a new diocese. I have no idea how to find out which diocese a parish was in on any date. I am afraid that categorizing Anglican clergy by diocese is completely impractical. We should categorize them by historic county. I think Anglican parish registers state the county of the parish a lot more often than they state the diocese.