Gwenwynwyn was the last major ruler of south Wales before the completion of the Norman Conquest. He was a grandson of Owain Gwynedd and ruled southern Powys from 1195, having taken control following the death of the previous ruler. This brought him into conflict with Llywelyn the Great, ruler of Gwynedd, who was keen to extend his own jurisdiction over the whole of Wales. King John favoured Gwenwynwyn until a marriage alliance was made between Llywelyn and John's illegitimate daughter. The two native princes then kept their distance until 1208. As a result of Gwenwynwyn's activities, John confiscated his lands and allowed Llywelyn to steal Ceredigion and Powys. Gwenwynwyn did not get his territory back for two years, but his resentment towards the English led him into an alliance with Llywelyn, which lasted from 1212 until 1216, when John restored some of Gwenwynwyn's property and the two princes fell out again. Llywelyn invaded Powys, and Gwenwynwyn is believed to have died or been killed that same year.