Corneille wrote his masterpiece Le Cid in 1637. The tragedy is based on on the play Mocedades del Cid (1621) by Guillem de Castro. Le Cid means Al Sayyid in Arabic, which roughly means The Lord). Cid Campeador is the name given in histories, traditions and songs to the most celebrated of Spain's national heroes. His real name was Rodrigo or Ruy Diaz (i.e. son of Diego), a Castilian noble by birth. He was born at Burgos about the year 1040.
Under Sancho II, son of Ferdinand, he served as commander of the royal troops. In 1072 Sancho was assassinated and Alfonso became King, and later, he banished The Cid from the kingdom. At the head of a large body of followers, the Cid joined the Moorish King of Saragossa, in whose service he fought against both Moslems and Christians. It was probably during this exile that he was first called the Cid. He was very successful in all his battles.
Le Cid is considered Pierre Corneille's finest play and marks the beginning of French tragedy. But its publication gave rise to heated arguments about the rules of tragedies (in terms of time, place and action). The immediately following tragedies respected these (Horace (1640), Cinna (1643), Polyeucte. These three plays and Le Cid are collectively known as Corneille's Classical Tetralogy.