Gerald of Wales was an ecclesiastic, a servant and critic of the Angevin kings, and a prolific and vitriolic writer. Born in Pembrokeshire of mixed Norman and Welsh blood in the middle years of the twelfth century, he was appointed archdeacon of Brecon in 1175, but that was the highest office he attained, despite his indefatigable efforts in the years 1198-1203 to become not merely bishop, but archbishop, of St Davids. His death was reported in 1223. His Instruction for a Ruler (De principis instructione) is of interest for three main reasons: it provides a detailed and...