The Song of Roland begins with the last city standing in Spain as Saragossa which is held by Marsilla, a Muslim king. Marsilla is terrified by the great wrath of Charlemagne, the Frank king conquering near all of Muslim Spain for the past seven years and demanding the conversion to Christianity of all his conquered people. Charlemagne tires of fighting and instead wants peace. Roland, Charlemagne's "right -hand man", selects his step-sire Ganelon to pose as messenger on Charlemagne's behalf. Ganelon has long hated his stepson for holding higher esteem and suspects Roland of desiring his death at the hands of the pagans. Ganelon finds his chance for revenge upon Roland while meeting with the Saracens. The betrayal of God and his people costs Ganelon everything.
At the request of Ganelon and Naimes, Charlemagne agrees to a treaty with Marsilla in order to make a peaceful conversion. Charlemagne will not allow any of his inner circle of vassals go as messenger (this includes Roland). Because of this, Roland then nominates Ganelon for the position. Ganelon believes Roland's intentions are for him to die at the hands of the pagans (reason being that the same had happened to two previous messengers with similar intentions). Ganelon does not deny the nomination but instead takes it as a chance for revenge upon Roland and swears this in front of the stepson himself. Charlemagne bestows the staff and glove to Ganelon who let it drop foreshadowing the future betrayal.
When Ganelon comes to meet the Saracens, he tells them that Roland is to blame for the brutality of the Franks. He vows that if Roland were dead there would be peace. In a public meeting, Ganelon is nearly killed by Marsilla for offering the ultimatum of death or conversion. In private, Blancandrin explains the conspiracy offered by Ganelon. The Saracens know that Charlemagne will surely beat them with a planned attack and guide Ganelon to act as if he is following Charlemagne's orders so Ganelon departs with the people and treasure.