The article discusses the historical and literary origin of Cid - a Castilian knight of the times of the re-conquest - who in an oral form through Latin and Arabian chronicles and written in Spain epic poems and lyrical songs entered the world literature to become one of its most vital theme. At the source of Cid's popularity, in Spanish writing, compared only to the figure of don Juan, lies the value of the first literary creation of the protagonist - 13th century 'Song of Cid', as well as the stage version of a young Cid's endeavors by Guillén de Castro. The latter inspired Pierre Corneille to composing the famous drama 'Le Cid', which became the source text of the congenial translation into Polish by Jan Andrzej Morsztyn. A review of the most important literary creation of Cid is here connected with the analyses of its Polish translations.