The monastic community founded by St Millán in the 6th century became a pilgrimage site. A Romanesque church was built at the original Suso site to honor St Millán, where the first literature in Castilian was produced. In the 16th century, the community moved to the new Yuso monastery below Suso. The Spanish language originated in these monasteries, which span important periods in Spanish history from Mozarabic to Baroque styles.