Historically, the marquis of Brittany Roland was a Frankish seneschal (or commander) in Charlemagne's service, who was killed in the Battle of Roncevaux Pass by the Basques on 15 August, AD 778. He was the nephew of Charlemagne, but was brought up by his mother (the Lady Bertha) as a beggar, living in a cave near Sutri, Italy. At the age of 12, he was told the truth and acknowledged by Charlemagne.
Legend has embroidered his tale into the epic tale of the noble Christian killed by Islamic forces, which forms part of the medieval Matter of France. Roland's tale is retold in the eleventh century poem The Song of Roland, where he is armed with a horn and a sword named Durandal. See Orlando for his later history in Italian verse, leading to the epic Orlando Furioso by Ludovico Ariosto.
In Germany the meaning of Roland changed in Bremen towards a symbol of freedom. In that time this meant an opposition of free citizens against the power of the church and for civil rights. To build a Roland statue became famous among some cities in the middle age in Europe.
In Catalonia Roland (or Rotllà as Catalan people say) became a mythical powerful giant. Lots of places in Catalonia (both North and South) have a name related to Rotllà.