Bosman is a young villager from a frontier settlement in Arthur's kingdom. He crosses paths with Arthur while the king travels incognito as a wandering commoner, investigating emerging threats to the realm's peace, specifically the Viking King. Bosman joins forces with Arthur, another youth named Pete, and their animal companions, forming Arthur's traveling party for the journey. Throughout their travels, Bosman and Pete remain unaware of Arthur's true royal identity.

As part of Arthur's group, Bosman aids in the quest to confront and defeat the Viking King. He assists Arthur, who sometimes adopts the disguised heroic persona of the Prince on the White Horse to combat threats while preserving his anonymity.