The Tudors also claimed descent from Cadwaladr to legitimize their authority over Britain as a whole. Owen Tudor claimed descent from Cadwaladr and used a red dragon badge. When Henry Tudor landed in Wales in 1485, he adopted the red dragon flag and claimed to be returning in fulfilment of the prophesies of Merlin as recorded by Geoffrey of Monmouth. After his victory at the Battle of Bosworth Field Henry was greeted at the gates of Worcester with a poem asserting,