This is a collection of 236 boxes containing around 36,000 documents. It is an open collection that has been formed over time like the Collection of Codices, and includes manuscripts which are very heterogeneous in terms of both their subject matter and their type, and which range from the 12th to the 20th centuries.

Among many other notable documents, pride of place is taken by the personally signed letters from Prince Henry the Navigator to the prior and monks of Alcobaça, and from Vasco da Gama to the captains of the Indies fleet, which are respectively dated 1432 and 1502, and the original draft of the Treaty of Tordesilhas, dated 7 June 1494.