Gunter

This king of Denmark withheld tribute from Arthur. Gunter’s treacherous brother, Odulf, sent a message to Arthur telling him of Gunter’s decision. Arthur conquered Denmark, killed Gunter, and appointed Odulf to the throne. Gunter had another brother namd Ascil.

This episode is found in Geoffrey Gaimar’s chronicle; other chronicles mention Arthur’s conquest of Denmark but do not name its king.