1262 following Llywelyn's raids in the Welsh Marches. Edward, however, was forced to pull his armies out of Wales due to internal conflicts in England. Llywelyn retaliated by campaigning against the English Marcher Lords in a devastating campaign which led King Henry (who had been considerably weakened by the Second Barons' War) to open negotiations with Llywelyn at the Treaty of Montgomery which won Llywelyn much land at the expense of the defeated Marcher Lords. References Battles involving England Battles involving Wales 1257 in Wales 13th century in Wales Conflicts in 1257 England–Wales relations