The battle unfolded after the army of Abd al-Rahman III launched toward the northern Christian territories in 934. Abd al-Rahman III had gathered a large army of caliphal fighters, with the help of the Andalusian governor of Zaragoza, Abu Yahya. The Leonese king Ramiro II led the counterattack with an army constituted of his own troops, those of Castile under Count Fernan Gonzalez and the Navarrese under García Sánchez I. Arab witnesses chronicle a spectacular eclipse of the sun that took place on the first day of the battle: