chunk: Charlemagne's army is fighting the Muslims in Spain. They have been there for seven years, and the last city standing is Saragossa, held by the Muslim King Marsile. Threatened by the might of Charlemagne's army of Franks, Marsile seeks advice and his wise man, Blancandrin, councils him to conciliate the Emperor, offering to surrender and giving hostages. Accordingly, Marsile sends out messengers to Charlemagne, promising treasure and Marsile's conversion to Christianity if the Franks will go back to France.
  Charlemagne and his men, tired of fighting, accept his peace offer and select a messenger to Marsile's court. Protagonist Roland, Charlemagne's nephew, nominates his stepfather Ganelon as messenger. Ganelon, who fears to be murdered by the enemy and accuses Roland of intending this, takes revenge by informing the Saracens of a way to ambush the rear guard of Charlemagne's army, led by Roland, as the Franks re-enter Spain through the mountain passes.