The Medieval Manuscript Collection consists of documents dating from the 13th century. The collection consists of folios of music, law, the Bible, theology, Psalters, the Book of Hours, Science, Liturgy, as well as more modern representations of the medieval style. Although most of the pieces are from northern Europe, the reproductions are from the Middle East and North Africa. The works include notable authors such as Justinian, Thomas Aquinas, and John Chrysostom.
You can find more details about the Medieval Manuscript Collection here.