It rankled with Henry II that Wales did not pay to him the honour she had paid to his great-grandfather, William the Conqueror.
When Henry II came to the throne in 1154, Welsh princes no longer paid England the respect they had paid to his great-grandfather, William the Conqueror. But then one of them, Cadwallader, came and begged Henry to help win back his lands from his brother Owen Gwyneth. Henry saw his chance, and at a council in Northampton in July, 1157, resolved to march on North Wales.