Owain Gwynedd was born in Anglesey around 1100, the second son of Gruffudd ap Cynan. He traced his descent back to Rhodri Mawr, the great 9th-century ruler of Wales.
With his brothers Cadwallon and Cadwaldr, Owain led the resistance to the Normans in the last years of his father’s reign and continued the expansion of the realm. Cadwallon’s death in battle in 1132 made Owain the heir to Gwynedd, and on his father’s death in 1137 he inherited a kingdom that covered most of north Wales. At first Owain shared the throne with his surviving brother, but after 1143 he became the sole ruler of Gwynedd.
Owain took advantage of political instability in England to extend his territories, but in 1157 King Henry III invaded Gwynedd. The Welsh and English armies met at the Battle of Ewloe, in which the English were defeated. A simultaneous naval attack on Anglesey was also repelled. Despite these successes, however, Henry’s army still greatly outnumbered the Welsh. Owain was obliged to sign a truce that stripped him of the territory he had gained, and forced him to do homage to the English king.
In 1165 Henry invaded again, and Owain led an alliance of Welsh princes to meet the English forces in battle once more. Not for the first – or last – time in Wales, the weather intervened, and torrential rain forced Henry to retreat. It was to be the last time the English attempted an invasion during Owain’s reign. Over the following years he regained the territories that he had lost, and until his death in 1170 was able to describe himself as ‘Prince of Wales’ – the first to have used the title.
Owain was buried in Bangor Cathedral, the church that his father had paid to be rebuilt.