Old Spanish, also known as
Old Castilian or
Medieval Spanish , is an early form of the
Spanish language that was spoken on the
Iberian Peninsula from the 10th century until roughly the beginning of the 15th century, before a consonantal readjustment gave rise to the evolution of modern Spanish. The poem
Cantar de Mio Cid (
The Poem of the Cid), published around 1200, remains the best known and most extensive work of literature in Old Spanish.