<P> Charlemagne and his men, tired of fighting, accept his peace offer and select a messenger to Marsile's court . The 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 France through the mountain passes . </P> <P> As Ganelon predicted, Roland leads the rear guard, with the wise and moderate Oliver and the fierce Archbishop Turpin . The Muslims ambush them at Roncesvalles and the Christians are overwhelmed . Oliver pleads with Roland to blow his horn to call for help, but Roland tells him that blowing his horn in the middle of the battle would be an act of cowardice . If Roland continues to refuse, Oliver will not let Roland see his sister again whom Roland loves the most . However, Archbishop Turpin intervenes and tells them that the battle will be fatal for all of them and so instructs Roland to blow his horn oliphant (the word is an old alternative to "elephant", and was used to refer to a hunting horn made from an elephant tusk) to call for help from the Frankish army . The emperor hears the call on their way to France . Charlemagne and his noblemen gallop back even though Count Ganelon tries to trick them . </P> <P> The Franks fight well, but are outnumbered, until almost all Roland's men are dead and he knows that Charlemagne's army can no longer save them . Despite this, he blows his olifant to summon revenge, until his temples burst and he dies a martyr's death . Angels take his soul to Paradise . </P> <P> When Charlemagne and his men reach the battlefield, they find the dead bodies of Roland's men, who have been utterly annihilated . They pursue the Muslims into the river Ebro, where the Muslims drown . Meanwhile, Baligant, the powerful emir of Babylon, has arrived in Spain to help Marsile . His army encounters that of Charlemagne at Roncesvalles, where the Christians are burying and mourning their dead . Both sides fight valiantly . When Charlemagne kills Baligant, the Muslim army scatters and flees, leaving the Franks to conquer Saragossa . With Marsile's wife Bramimonde, Queen of Saragossa, Charlemagne and his men ride back to Aix, their capital in France . </P>

Describe charlemagne in the epic the song of roland