Hubert Walter, Archbishop of Canterbury, died 13 July 1205, which provides a definite terminus. The styling of Llywelyn Fawr as Prince of North Wales [princeps Norwalliae] could mean as early as 1194, when he removed his uncle Dafydd from power, or as late as after 1200 when he obtained control of the remainder of Gwynedd from his cousin Gruffydd. Perhaps if we can find more detail as to the career of Robert, bishop of Bangor and abbot of Bildewas, co. Salop & c., this time frame could be better defined.
It is interesting to note that the issue has to do with the husband of 'M' [Margaret, mother of Llywelyn] and the issue of his relations with one 'Guladus' or Gwladys, a kinswoman of 'M'. While an Anglo-Welsh heritage is not ruled out for either woman, on the surface it would reinforce the indentification of Margaret with Margaret ferch Madog, daughter of Madog ap Maredudd of Powys (d. ca. 1160).