King Arthur....... perhaps!
Riothamus (also spelled Riutimus or Riotimus) was a Breton-Romano military leader, and King of Brittany and possibly lands in southern England. He was active circa AD 470 and lead a army against the Goths in alliance with the Romans. He is called “King of the Bretons” by the 6th-century historian Jordanes but the extent of his realm is unclear. Some Arthurian scholars identify Riothamus as one of the possible sources of the legendary King Arthur.
The miniature is from the Footsore Miniatures 28mm Dark Age range
"walk the battlefield in the morning, wargame in the afternoon"™
cheers
Matt