The Salamanca Papers (Catalan: Papers de Salamanca) refer to the 300,000 documents and 1,000 photographs confiscated from the Catalan government after the Spanish Civil War and transported in 12 railway freight wagons to the city of Salamanca to be stored in what was later to become Spain's Civil War Archive (Archivo General de la Guerra Civil Española).
The return of the documentation to the Catalan autonomous government was subject to much polemic in the 1990s and early 2000s,[1] as well as numerous acts of violence at the moment of their physical transfer. The ad hoc committee of experts declared in 2004 that the documents should be returned to their legitimate owners. The documents were finally transferred in 2005.
More informaiton on the Wikipedia page [1]