 Gerald had pleaded not only his own cause, but that of St David's as a Metropolitan archbishopric (and thus of the same status as Canterbury) reviving the earlier claims of Rhygyfarch and Bernard, Bishop of St David's.It was in connexion with this cause that he wrote his books "De jure Menevensis Ecclesiâ" and "De Rebus a Se Gestis".Gerald returned, and his cause was now supported by the Princes of Wales, most notably Llywelyn the Great, and Gruffydd ap Rhys II, while King John, frequently in conflict with the Welsh, warmly espoused the cause of the Archbishop of Canterbury.