The First Dynasty of Gwynedd was the founding dynasty of the Kingdom of Gwynedd, and ruled over the kingdom for almost four hundred years. Its main branch may also be referred to as the Maelgyning, named after Maelgwn Gwynedd, an important king of the dynasty. This branch was based in Aberffraw. Its other main branch was descended from Cynlas, and was based in Rhos. The two branches at times competed for the title of king.