There are events in the History of Spain that are significant for their importance or for the enormous significance that they acquire over time. Simple meetings, pacts or arrangements, which sometimes go unnoticed, or are even little known, and which really are the foundations for the future, charting a different course or weaving the fabric of destiny. Thus, one of these important and transcendental events in our history was the Compromiso de Caspe (Compromise of Caspe), since, according to some historians, it was the essential step towards the constitution of the Hispanic Monarchy.

Background to the period

Before getting down to business and explaining what that compromise consisted of and the importance it had for the future, I would like to give a brief introduction to the period, and for that we have to travel back to the Spain of the early 15th century. At that time, the territory was divided between two incipient Christian kingdoms: the Kingdom of Aragon, which, having completed the reconquest, was looking towards the Mediterranean to expand its dominions; and the Kingdom of Castile, which had yet to complete the task of reconquest and lacked the last obstacle, the Nasrid Kingdom of Granada, the third in discord on the peninsula.

It so happened that Enrique III “The Sorrowful”, King of Castile, died in 1406, just a year after giving birth to his only son and heir, the future Juan II of Castile. The deceased king established in his will that, during his son’s minority, the regency of the kingdom would be assumed by his widow and mother of Juan, Caherine of Lancaster, and his brother Fernando. The boy’s education was the responsibility of the chief steward Juan de Velasco, the chief justice Diego López de Estúñiga, and Pablo de Santa María, Bishop of Cartagena.

Despite the testamentary stipulations, disagreements between the co-regents soon arose, driven by intrigues of the nobility. As a result, an agreement was reached to divide the kingdom into two halves, with Fernando taking the southern part, i.e. from the south of the Sierra de Guadarrama to the Nasrid kingdom of Granada. The rest of Castile remained under the influence of Catherine.

Fernando of Antequera

Fernando descended from the Castilian Trastamaras as the son of Juan I of Castile, and through his mother’s line he was of Aragonese descent, as his mother, Eleanor, was the daughter of Pedro IV “the Ceremonious”. From the time he took charge of the southern part of the peninsula, he was determined to resume military action against the Nasrid kingdom and won victories at Pruna and Zahara de la Sierra.

After completing two years of truce, signed with the Nasrid king Yusuf III following a defeat, he resumed his campaigns and conquered the important town of Antequera, a nickname by which he would be known from that moment onwards. Fernando began to stand out, not only in Castile but also beyond its borders.

In the other kingdom of the peninsula, in the Crown of Aragon, Martin I “the Humane” died without descendants in 1410, initiating an unprecedented process that had many democratic overtones. Actually, Martin I had a son, Martin “the Younger”, who was king of Sicily, but died before his father. The young man had a son, Fadrique of Aragon, who could not be a candidate because Martin I “The Humane”, his grandfather, died before he could legitimise him.

Thus, faced with the death of Martin’s only heir, the lack of legitimisation of his grandson Fadrique, the unsuccessful marriages, and the disputes and refusals over the appointments of the different candidates to the throne, which provoked various clashes between the deputations, the institutions of the Crown began to develop a process that would be directed by the different parliamentarians of the Diputaciones Generales, representatives of 15th century society, and which would be aimed at restoring the monarchy and maintaining the unity of the Crown of Aragon in a civic and peaceful manner.

Of all the candidates proposed, Fernando de Antequera was the pretender closest to the King of Aragon. It was curious because a Castilian, a member of the house of Trastámara, was a firm candidate to reign in the Crown of Aragon. But first, the manner and form of this consensual designation had to be worked out.

The Parliament of Calatayud and the Concord of Alcañiz

In June 1410, with extreme speed, the representatives of the municipal corporations of Zaragoza, Valencia, and Barcelona agreed to set up a General Parliament of the Crown of Aragon for the purpose of appointing a new sovereign. The meeting took place in Calatayud in mid-May 1411. Unable to reach a joint agreement, they agreed that the representatives of Aragon would meet in Alcañiz, the Catalans in Tortosa and the Valencians in Trahigera, imposing a system of ambassadors to communicate with each other until an agreement was reached.

These first steps were followed by a series of important events: The strong opposition of the Count of Urgel, another of the candidates for the Crown, to the formula agreed by the Calatayud Parliament; the assassination of the Archbishop of Zaragoza, president of the Cortes; instability, quarrels, the threat of civil war and the closure of the three parliaments mentioned above. Subsequently, new parliaments were formed and the church and Pope Luna intervened. Tremendous chaos and a welter of palace intrigues and interests, like something out of a film, which led, not without effort, to the Concord of Alcañiz.

On 15 February 1412, the parliaments of Catalonia and Aragon signed the Concord of Alcañiz, in which it was established that nine commissioners from the three states, divided into three groups in three grades, with three members of each grade representing the interests of the Crown, would meet in the Aragonese town of Caspe to deliberate and decide on the candidate who would occupy the throne of Aragon, provided he obtained the minimum number of six votes.

Despite the goodwill, another dispute almost broke out because the kingdom of Valencia was unable to unify its parliament, almost even leading to armed conflict, but in the end, the expected agreement was reached and they were convened on 29 March 1412, with two months to reach an agreement. To ensure that nothing was lacking, on 2 January 1412, a papal bull recognised and validated the system and the process of designating the royal candidate.

Compromise of Caspe and Proclamation of the King of Aragon

With the main support of Saint Vicente Ferrer, a delegate for Valencia, and with a total of 6 votes out of a total of 9 representatives of the states of the Crown of Aragon, on 25 June 1412, according to the original notarial record, Fernando de Antequera, a Castilian, was proclaimed King by means of a parliamentary procedure.

The Caspe Compromise was an unprecedented and transcendental event because of what it meant for the future of the Hispanic Monarchy and because of the way in which a monarch was designated. The ruling was welcomed in Aragon, although not so much in Valencia and less so in Catalonia. Soon, the Count of Urgel, in displeasure, would start a civil war with the support of English, Gascon and Navarrese troops.

The Trastamara family branch was left to deal with the present and to build the roads to union and prosperity in the future. Apart from the Castilian king’s minority, the regency of Catherine of Lancaster, the gathered power, the intrigues, the agreed liaisons, and the deaths, everything came together. The point was that Juan II, heir to the throne of Castile, was the father of Isabel the Catholic Queen. And Juan II of Aragon, son of Fernando of Antequera, in turn uncle of Juan II of Castile, was the father of Fernando the Catholic King. Both Isabel and Fernando, second cousins, married to unite two kingdoms and consolidate a powerful crown that would begin to take giant steps towards unprecedented splendour.

Small acts, hardly of any importance, but which marked a before and after. The Compromise of Caspe, in addition to the novel system of electing the monarch, served to unite two crowns and consolidate a kingdom that would be the forerunner of the empire where the sun never set.