Britain and Welsh Triads

There are three pillars of the social state in the Isle of Britain: the voice of the country, royalty, and judicature, according to the regulation of Prydain the son of Aedd the Great...

The three heroic sovereigns of the Isle of Britain: Cynfelyn Wledig, Caradog the son of Bran, and Arthur; because they conquered their enemies, and could not be overcome but by treachery and by plotting...