Milocrates
A barbarian island king who abducted the wife of the King of Illyricum.
Gawain and a fleet of Romans blew ashore on their way to Jerusalem and immediately came into conflict with Milocates when Gawain killed one of his stags. Milocates sent for help from his brother, named either Egesarius or Buzafarnan.
Milocates was killed in the ensuing war, his island was occupied by Romans, and the Queen of Illyricum was returned to her home.
Source
De Ortu Waluuanii Nepotis Arturi | Late 13th century