Consists of 637 Spanish documents, collected by Marden, divided into two groups: documents originating from the town of Burgos and several towns around Soria and documents from the town of Alarcon. The first group--170 documents--contains deeds, mortgages, wills, probate documents, and documents drawn up to establish genealogies, all apparently intended to prove rights to inherit capellanias; the second group, consisting of 467 documents, concerns the affairs of the seigneurial town of Alarcon, south of Cuenca. Most of these documents are legal files and illustrate the governance of a town which belonged to one of the most powerful grandees of 16th-century Spain, the Marques de Villena. The wool trade and industry of the area figures significantly in the documents.

Later additions to the collection (document numbers 638 to 642) include the earliest document in the collection, dated 1347, a power of attorney granted to "certain persons" in the town of Medina del Campo, a Papal dispensation (1650) for a marriage, and an inventory (1630) of inherited property.