King Arthur @ Vortigern (Gwrtheyrn Gwrtheneu), a native chieftan of the Britons
The cited information was published by Perennial Library, Harper & Row, New York, 1986 (Ref: Vortigern (Gwrtheyrn Gwrtheneu), a native chieftan of the Britons) The author/originator was Norma Lorre Goodrich.