Aldroen, Adroenus, Aldroein, Audrien

King of Brittany two generations before Arthur.

When the Archbishop Guethelin, Aldroen's kinsman, came to Brittany to beg for Aldroen's help in driving the Picts and Huns from Britain, Aldroen sent his brother Constantine, Arthur's grandfather, to accomplish the task and assume the throne of the island.