The Cid, or Cid Campeador (lord champion), a popular hero of Spain, whose real name was Ruy or Rodeigo Diaz, born at the castle of Bivar, near Burgos, about 1040, died at Valencia in 1099. He figures prominently in early Spanish literature, but his genuine exploits are so mixed up with fictions that it is impossible to ascertain his real history. According to the most consistent accounts, he belonged to a powerful family, and became standard-bearer and commander of the royal troops to Sancho II., king of Leon and Castile. At the siege of Zamora the king was treacherously slain, and his brother Alfonso, the next heir to the throne, was suspected of having been privy to the deed. Diaz compelled Alfonso to declare his innocence by an oath, with terrible maledictions in case of falsehood, before he would permit him to occupy the throne. His life was spent in combat with the Moors, to whom he became a terror on account of his constant success. The designation el Seid, corrupted to Cid in Spanish, was given to him by the Moors in acknowledgment of his prowess, while the Spaniards whom he protected and avenged called him el Campeador, the champion; and finally the two epithets combined were almost universally applied to him.

He captured Valencia about five years before his death, and established himself as its ruler. His wife held the place about three years after he died, and was then forced to fly to Castile, where she died in 1104. He had a son, who was killed by the Moors in battle, and two daughters, one of whom was married to the count of Barcelona and the other to the prince of Navarre. The exploits of the Cid soon became the subject of poetry and romance, and he became in the popular mind the pattern of a Christian warrior, invincible in battle and unblemished in character. Fictions were mingled with his actual achievements, until his identity was well nigh lost; and some writers have even contended that he was only a myth. The "Poem of the Cid," composed about the year 1200, is one of the earliest and most vigorous specimens of Spanish verse. It contains nearly 4,000 lines, and professes to give a continuous account of the doings of its hero. The author is often spoken of as the Homer of Spain, but his name is unknown. The "Chronicle of the Cid," a prose production of the 13th century, is also of unknown origin.

There are three editions of this, dated in 1541, 1552, and 1593. Besides these there are numerous romances and ballads on the same subject, many of which have been translated into English by Lockhart. A complete collection in the original is contained in Augustin Duran's Romancero general. The old " Poem of the Cid" was originally published by Sanchez in the first volume of his Poesias castellanas anteriores al siglo XV. (4 vols. 8vo, Madrid, 1779-'90), and reprinted by Ochoa (8vo, Paris, 1842). Excellent translations from it were made by Herder in German, and by J. Hookham Frere in English. Southey's "Chronicle of the Cid" is made up of free versions' and compositions from the old poem, the prose chronicle, the ballads, and the general chronicles of Spain. It furnishes the stories and traditions in a very pleasing form. Of the dramas founded on this romantic subject Corneille's Cid is the best known.