Since the sixteenth century, there have been stories circulating that a Welsh prince of the late twelfth century CE discovered new lands on the western side of the Atlantic and led an expedition to settle a group of his followers there. According to the legends, their descendants intermarried with native Americans and influenced the language and culture of the Mandan people of the Missouri valley. Did Madoc ap Owain really exist and should he be credited with the European discovery of North America?