An old Galloway legend linked the origins of the family to Cullo O'Neill, believed to have been born in Ireland, a son of the family of O'Neills of Clanaboy. Cullo O'Neill served in the army of Edward Bruce, King of Ireland, brother of king Robert the Bruce of Scotland. In around 1316 he was chosen by Edward Bruce as Captain of horse in his army. He later became Sir Cullo O'Neill. In about 1317 king Robert the Bruce of Scotland knighted Captain Cullo og Neil (o’Neil) and chose him to be his standard-bearer and Secretary of State. King Robert the Bruce granted Sir Cullo og Neil the lands of Achawan or Auchwane in Wigtownshire. In 1331 Sir Cullo Og Neil died and left his estate to his eldest son Sir Godfrey, who assumed the surname of MacCullog. (MacCullough / MacCullo’c).