Madoc, also spelled Madog, ab Owain Gwynedd was, according to folklore, a Welsh prince who sailed to America in 1170, over three hundred years before Christopher Columbus's voyage in 1492. According to the story, he was a son of Owain Gwynedd, and took to the sea to flee internecine violence at home. The "Madoc story" legend evidently evolved out of a medieval tradition about a Welsh hero's sea voyage, to which only allusions survive. However, it attained its greatest prominence during the Elizabethan era, when English and Welsh writers wrote of the claim that Madoc had come to the Americas as an assertion of prior discovery, and hence legal possession, of North America by the Kingdom of England.
The "Madoc story" remained popular in later centuries, and a later development asserted that Madoc's voyagers had intermarried with local Native Americans, and that their Welsh-speaking descendants still live somewhere in the United States. These "Welsh Indians" were credited with the construction of a number of landmarks throughout the Midwestern United States, and a number of white travelers were inspired to go look for them. The "Madoc story" has been the subject of much speculation in the context of possible pre-Columbian trans-oceanic contact. No conclusive archaeological proof of such a man or his voyages has been found in the New or Old World; however, speculation abounds connecting him with certain sites, such as Devil's Backbone, located on the Ohio River at Fourteen Mile Creek near Louisville, Kentucky.
Madoc's purported father, Owain Gwynedd, was a real king of Gwynedd during the 12th century and is widely considered one of the greatest Welsh rulers of the Middle Ages. His reign was fraught with battles with other Welsh princes and with Henry II of England. At his death in 1170, a bloody dispute broke out between his heir, Hywel the Poet-Prince, and Owain's younger sons, Maelgwn, Rhodri, and led by Dafydd, two the children of the Princess-Dowager Cristen ferch Gronwy and one the child of Gwladus ferch Llywarch. Owain had at least 13 children from his two wives and several more children born out of wedlock but legally acknowledged under Welsh tradition. According to the legend, Madoc and his brother (Rhirid or Rhiryd) were among them, though no contemporary record attests to this.