The King of Castile consulted the Cid as to the reply which he should give to his brother.
"Endeavour," said Don Rodrigo to him, "to avoid war with your brother, but if he perseveres in his provocations, make war against him, without, however, forgetting that he is your brother; but to enter into his kingdom you must pass through that of Leon, and to do so without the consent of Don Alfonso would be only to make another enemy."
Don Sancho and Don Alfonso met in Sahagun, and arranged that the latter should allow the Castilian army to pass through the kingdom of Leon. As a result of this arrangement, Don Sancho sent Alvar Fañez Minaya to challenge Don Garcia.
He accepted the challenge, and collected a large army, with which he prepared to march against his brother, who was advancing in great force towards Galicia. His soldiers, however, who were very much discontented on account of war having been declared against Castile, as they foresaw its disastrous consequences, revolted at the moment of setting out, and killed Rui-Ximenez in the presence of the king, for they believed that it was he who had given evil counsels to Don Garcia.
This occurrence caused the breaking up of the army of the King of Galicia, and thus the Castilians penetrated into his kingdom, and Don Sancho made himself master of several fortified places, and especially of the entire Portuguese portion of the kingdom.
After a time, however, Don Garcia mustered another large army, and sallied forth to encounter his brother. The battle was fierce, the two kings fighting at the fronts of their respective troops, and after a combat, lasting for half a day, the Castilians were thrown into disorder. Don Garcia succeeded in making Don Sancho his prisoner, and having given him into the charge of six of his followers, he set out in pursuit of the fugitives.
"Give me my liberty, cavaliers," cried Don Sancho to those who were guarding him, full of anger at not being able to stop the flight of his disordered army, and of shame at finding himself a prisoner. "Let me free, and I promise you rich rewards, and I also give you my word that I will not cause any further injury to your country."
"For all your kingdom we would not do it," replied his guards, "for we should then be traitors to our lord and king. You must await the return of Don Garcia, and he can act as he pleases."
Alvar Fañez Minaya saw from a distance the capture of Don Sancho, and, spurring his horse towards those who were guarding him, he cried out—
"Traitors, set my lord and king at liberty!"