 These were the Latin-based Romance languages of Castilian, Aragonese, Catalan, Galician, Aranese, Asturian, Leonese, and Portuguese, and the ancient language isolate of Basque.Throughout the century, Castilian (what is also known today as Spanish) gained a growing prominence in the Kingdom of Castile as the language of culture and communication, at the expense of Leonese and of other close dialects.One example of this is the oldest preserved Castilian epic poem, "Cantar de Mio Cid", written about the military leader "El Cid".