Introduction: the geographical, political and administrative setting

At the time of the Black Death, the Iberian Peninsula contained a number of states. For the sake of convenience, the term Spain is used to denote the territory covered by the modern Spanish state with the exception of the Muslim Kingdom of Granada but including Rossillón, which today belongs to France (Roussillon). There were, accordingly, three Spanish kingdoms or states: the Crown of Castile, the Kingdom of Navarre and the Kingdom of Aragon. The Crown of Castile comprised the former Kingdom of Castile or Old Castile (the provinces of Santander, Burgos, La Rioja, Soría, Segovia, Ávila, Valladolid and Palencia), and the former Kingdom of León (the north-western provinces of Galicia, Asturias and León). After centuries of successful war against the Muslim Moors, the Crown of Castile also included New Castile, Extremadura, Andalucia, i.e., the conquered parts of Al-Andalus, and the former Kingdom of Murcia.

The Kingdom of Aragon was coextensive with the modern Spanish region of Aragon, consisting of the three provinces of Zaragoza, Teruel and Huesca, and with the city of Zaragoza as political centre, containing approximately 200,000 inhabitants at the time. It should not be confused with the Crown of Aragon, which was a composite feudal state with clear confederative structural features. On the eve of the Black Death, the Crown of Aragon comprised in Spain, in addition to the landlocked Kingdom of Aragon, the former Kingdom of Valencia with approximately 300,000 inhabitants, the Principality of Catalonia including Rossellón and Cerdaña (since 1659 French Roussillon with northern Cerdagne, Alta Cerdaña), containing around 470,000 inhabitants, and the Balearic Islands, with around 45,000 inhabitants, in all approximately 1 million inhabitants. In addition, the Crown of Aragon also included the Kingdom of Sicily and Sardinia I. in Italy. The Crown of Aragon was primarily a state with maritime realms with the exception of the landlocked Kingdom of Aragon itself. This means that it had to be a big sea power and the commercial powerhouse of the region, which proved important for the history of the Black Death in Spain. The Kingdom of Navarre in north-eastern Iberia contained in the early 1300s 70,000–100,000 inhabitants.

There were also two non-Spanish kingdoms, namely the Kingdom of Portugal and the remaining Moorish realm of Al-Andalus, the Kingdom of Granada.