This was in thanks to the successful reigns of Gruffudd ap Cynan, king of Gwynedd, and his son Owain Gwynedd, which marked the beginning of the age of the princes.
Roedd hyn o ganlyniad i deyrnasiad llwyddiannus Gruffudd ap Cynan, Brenin Gwynedd, a'i fab Owain Gwynedd, a nododd ddechrau Oes y Tywysogion.