The article studies the campaigns and battles of the Cid from the standpoint of the general principles and methods of war. The poet, whether literate or not, is shown to have a good understanding of military matters, however obtained. The realistically described situations and procedures must often have been met with and employed in battle from ancient times to the Middle Ages. This may cast doubt on the notion that certain episodes in the Poema can definitely be shown to have specific Latin literary sources.