In the Iberian Peninsula, the use of writing as a means of communication dates back to the time of the Visigoths, although the ability to transmit information efficiently was solidified with the arrival of paper and the printing press in the 15th century. These advancements facilitated the production and sending of letters, which in turn allowed for more constant and effective contact between members of the nobility as well as between institutions and citizens.
Correspondence among nobles was not only a means to exchange news and maintain relationships but also a political tool. Letters could serve as instruments of power; a well-crafted missive could secure alliances, strengthen family ties, or even influence crucial political decisions. Correspondence thus became a reflection of the diplomacy of the time, where every word and every signature carried significant weight.
One of the great examples of the importance of correspondence in the Spanish nobility can be observed in the figure of the Catholic Monarchs, Isabella of Castile and Ferdinand of Aragon. Their correspondence not only allowed them to coordinate their actions in the unification of Spain but also helped them establish relationships with other European powers. Through their letters, marriage agreements were managed, and messages of support were sent to their allies, thus creating a web of loyalties that was essential for the consolidation of their power.