Page "El Cid" Paragraph 15

Almost immediately, Alfonso returned from exile in Toledo and took his seat as king of Castile and León.

He was deeply suspected in Castile, probably correctly, of having been involved in Sancho's murder.

According to the epic of El Cid, the Castilian nobility led by El Cid and a dozen " oath-helpers " forced Alfonso to swear publicly in front of Santa Gadea ( Saint Agatha ) Church in Burgos on holy relics multiple times that he did not participate in the plot to kill his brother.

This is widely reported as truth, but contemporary documents on the lives of both Rodrigo Diaz and Alfonso VI of Castile and León do not mention any such event.

El Cid's position as armiger regis was taken away and given to El Cid's enemy, Count García Ordóñez.