NIGHTBRINGER | The Arthurian Encyclopedia

Marius


A first-century King of Britain in Geoffrey’s chronicle. He succeeded his father, King Arviragus.

During his reign, he fought the Picts under Sodric in Scotland, but still bestowed Caithness on them. He was succeeded by his son, Coill.


Source
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138