 Nothing certain is known of Cynethryth's origins.Her name recalls the wife and daughters of King Penda—Cynewise, Cyneburh, and Cyneswith—which may indicate that she was a descendant of Penda.A tradition related by the 13th century "Vitae duorum Offarum" tells that she was of Frankish origin, and that for her crimes she was condemned by Charlemagne's justice system to be set adrift at sea in an open boat.