Urbigen, Urbigene, Urgain, Urgence, Urgennius, Urgent
In Geoffrey of Monmouth, Arthur’s Earl of Bath.
He fought in the Roman War and was killed at the battle of Soissons. His name is a variation of Urien, which also occurs in Geoffrey.
It seems that Geoffrey misinterpreted his sources, identifying two characters instead of one.
Sources
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138
Roman de Brut | Wace, c. 1155
Brut | Layamon, late 12th century to mid-13th century