In European folklore, Murgleis was the sword of Ganelon, the stepfather of Roland, as described in The Song of Roland. Ganelon was married to Charlemagne's sister and had a son with her. He resents his stepson's boastfulness and great popularity among the Franks and success on the battlefield. When Roland nominates him for a highly dangerous mission (possibly even suicidally dangerous) as messenger to the Saracens, Ganelon is so deeply offended that he vows vengeance. This vengeance becomes treachery as Ganelon plots with the pagan Blancandrin the ambush at Roncesvals.