This is one of the most important historical archives for the history of the old Realm of Aragon (kingdoms, principalities and dukedoms of Aragon, Catalonia, Valencia, Mallorca, Rosellon, Sardinia, Sicily, Naples and a long list of estates on the Mediterranean coast), Spain and the Mediterranean, and the oldest living archive in Europe.
Furthermore, the resources stored in the Archive document the international relations of the monarchs of Aragon with all the countries and states in the world known in Europe in the Middle Ages, particularly between the 13th and 16th centuries.
In short, the main territories on which documentation can be found, in addition to those that formed the old Realm of Aragon, are those listed below (with reference to the current name of the country to which they belong):
To summarise, it is a centre for the conservation and promotion of documentary heritage. Its scope goes beyond the frontiers of any one country and its resources include strong European content.