What is the cause of rolands death?

Roland's death in "The Song of Roland" is caused by his heroic yet tragic decision to sound the olifant (horn) to call for help from Charlemagne, which ultimately leads to his exposure and vulnerability in battle. He is mortally wounded by the Saracens during the fight at Roncevaux Pass, suffering from multiple injuries, including a fatal blow to the temple. His death symbolizes the themes of heroism and sacrifice in the epic.