The first theory we talk about is based on the research of Graham Philips1. He starts with the Nennius' story, the 9 th century monk. Nennius spoke of Arthur as one of the last native British leaders, who made a successful stand against the Anglo-Saxons. Nennius places Arthur in the late 5 th century and says that Ambrosius is the leader of an alliance of British kings. If he did existed, Arthur presumably ruled from the country's mightiest stronghold, according to Philips. The mightiest stronghold during that time was one in Powys, so that is were Arthur must have ruled.

To know who ruled the kingdom of Powys around 500 AD we need to look at the Harleian MS 3859. The family trees of important Dark Age chieftans are catalogued in there. The name that is found there is Owain Ddantgwyn (Owain White Tooth). He is the son of a warlord named Enniaun Girt.

However so far it is al an interpretation of the idea of a single man; Graham Philips. He assumed that the king might have lived in the mightiest stronghold. To tell whether Arthur was Owain we need to look further.

In the legend Arthur's father was called Uther Pendragon, which means in the old British language (Brythonic) “the terrible head dragon”. Philihps thinks that it is too much of a coincidence that Owain's father was also called the Dragon. More important is the nickname of Owain Ddantgwyn; “the Bear”. The word for the Bear in Brythonic looks pretty much the same like Arthur. In fact in modern Welsh, which derived directly from Brythonic, Arth is still the word of a bear.

Lets put al the facts together; Owain Ddantgwyn of Powys was just like Arthur the most powerful ruler in Britain. However, other historians found out that the nickname “the bear” wasn't Owains nickname2. It was the nickname of his son. There is no evidence that the father shared the nickname. Which means that Owain can't be Arthur after all.