Many nations have claimed the honour of 'discovering' America.
 Recent discoveries in north east and south east Brazil suggest
 that Negroid people inhabited South America up to 50,000 years ago. TheMongoloid peoples who migrated to the Americas across the land bridge from Asia at the end of the last ice age some 14,000 years ago displaced them. This latter group are the people we now refer to asIndians. There are still believed to be traces of Negroid characteristics in some of the inhabitants of Tierra del Fuego. Latest theories suggest that Stone Age Europeans may have followed the southern edge of the North Atlantic icecap from Spain to Newfoundland. There are also tales of the ancient Phoenicians, Romans, Polynesians, Japanese and Chinese having journeyed to the Americas. 

Saint Brendan, Brendan the Bold or Brendan, the Navigator. (484-577) Abbott of Clonefert in County Galway, Ireland. A legend popular in the Middle Ages describes his search for the fabled "Fortunate Isle". It says that Brendan travelled to the north and west where he encountered 'Islands of fire' (Iceland?), 'Islands of crystal' (icebergs?).  When he did find his paradise, he was not totally surprised to find a colony of his bretheren there. He explored the land for forty days until he came to a river that he could not cross. There, he was met by a young man who persuaded him to return home to Ireland. The story goes that his wanderings lasted seven years.  He must have gone fairly far south for him to call it the 'Fortunate Isle'. 

In 1977, a group of men sailed a leather boat (of the type used in St Brendan’s time) to North America, so proving the feasibility of such a journey. 

Eirik the Red (fl. 10th century), Norse explorer. He was exiled from Norway and Iceland for manslaughter in 982. He went on a voyage of discovery to look for and explore a new land sighted some fifty years earlier by a Norwegian sailor named Gunnbjorn. He called the land Greenland. He took colonists from Iceland to establish permanent settlements there in 986. 

According to the Greenlanders' Saga, in 986, Bjarni Herjolfsson set off to follow his father who had gone to Greenland with Eirik the Red's colonising expedition. He was subjected to north winds and then to fog. When he was eventually able to take bearings from the sun, he sailed for a day until he sighted a well-forested land with low hills. He decided it could not be Greenland and he did not risk landing on its shores. Herjolfsson sailed north along its shores for two days and then turned east and sailed for another seven days before eventually reaching his destination in Greenland. 

Lief Eiriksson, son of Eirik the Red. He sailed Herjolfsson's journey in reverse and put ashore in three identifiable areas of North America: Helluland - Flatstone Land; Markland - Wood Land; and Vinland where vines grew. He believed the land to be uninhabited and he seemed unaware of the size of the landmass. The Vikings returned from Greenland to Vinland, modern day New England, and stayed several years, eventually making contact with native Indians. There is compelling archaeological evidence of their presence. The Vikings appear to have visited North America on numerous occasions over the following centuries and travelled inland through the Great Lakes. The Mandan-Hidatsa Indians believe that the Vikings travelled as far a s the Rockies. 

Owain Gwynedd's mother was a Viking-Irish Princess, Madoc's mother was an Irishwoman, so it is extremely probable that  MADOC, would have been aware of the tales of St Brendan and Lief Eiriksson.