What trick did the Cid play on the Jews? Why did the Infantes of Carreon marry the Cid's daughters? Why did the two Infantes treat the Cid's daughter so badly?
El Cid and his companion, Martin Antolinez, trick the money lenders by giving them two ornately carved chests filled with sand. They let the money lenders believe that there is something of value in the chests and borrow 600 marks against the chests while making them agree not to open the chests for a year.
The Infantes marry the the Cid's daughters because they believe that marriage to a daughters of a man who had risen so quickly in the king's favor would be advantagous to them. Although the marriages began well, the Infantes were humiliated when they hide in terror after the escape of the Cid's lion. After the Cid recaptures the lion the Infantes are mocked and taunted at court. Even their subsequent bravery in battle did not repair their tarnished reputations. They then plan to humiliate the Cid by beating his daughters and leaving them in the woods. The daughters are found alive and recuperate, and the Cid takes revenge upon the Infantes.