In Guillaume le Clerc’s Fergus, the nephew of a malevolent king who besieged Lady Galiene of Lothian in the castle of Rocebourc.
Galiene obtained the services of Sir Fergus, Arthur’s knight, as her champion. Fergus slew Arthofilaus and defeated his uncle.
In the Dutch Ferguut, Arthofilaus becomes Macedone.
Source
Fergus | Guillaume le Clerc, 1200-1233