The moments of strength or weakness of the Spanish monarchy have been reflected in the regularity of documents' arrivals or conversely in the shortages of resources.

Subsequently, its strategic location between the kingdoms of León and Castile gave it a political role in that period.

However, it soon ceased to be part of the jurisdiction of Valladolid, because in 1465 King Henry IV of Castile ceded some powers to the city of Simancas to encourage it to remain faithful to him.

That meant that it had other uses, from being a weapons cache to acting as a state prison, functions that were served at the same time as being an archive.

The castle was not a place designed to house an archive, which means that there are some problems that have concerned archivists throughout history.

In the past, sharing archive space with a gaol increased the risk that the records might be reduced to ashes.