In mid-1311, John of Castile and the principal magnates of the Kingdom threatened Ferdinand IV by ceasing to serve him, if the monarch didn't satisfy their requests.
John of Castile and his followers demanded that the King replace his advisers and privates for John of Castile himself, the Dowager Queen, Infante Peter, Juan Manuel of Villena, Juan Núñez II de Lara and the Bishops of Astorga, Zamora, Orense and Palencia.
Juan Manuel of Villena remained loyal to Ferdinand IV, because on 15 October the King had given him all the royal pechos (tributes) and rights of Valdemoro and Rabrido, except for the moneda forera of both places and the martiniega (another tribute) de Rabrido, which had been granted to Alfonso de la Cerda.

With the desire to achieve peace in order to continue with the Reconquista, Ferdinand IV agreed to sign the Concord of Palencia on 28 October 1311 with John of Castile and the rest of the magnates, and whose clauses were ratified in the Cortes of Valladolid in 1312.
The King promised to respect the customs, fueros and privileges of the nobles, prelates, and subjects of the towns, and not to try to deprived the nobles of the rents and lands that belonged to the Crown.
Ferdinand IV ratified that the custody of his son, the Infante Alfonso, would be entrusted to his brother, Infante Peter, to whom also ceded the city of Santander.
The King ceded to John of Castile the municipality of Ponferrada, with the condition that he didn't establish any type of alliance with Juan Núñez II de Lara, although he didn't fulfill his word before eight days of the signing of the Concord.

In December 1311 Ferdinand IV meet in Calatayud with James II of Aragon.
At that moment was celebrated the marriage of Infante Peter of Castile and the Infanta Maria of Aragon, daughter of James II, although some authors indicate that the marriage was celebrated in January 1312.
At the same time, Ferdinand IV gave to James II his eldest daughter, the Infanta Eleanor of Castille, to be raised in the Aragonese court until she had the proper age to marry the Infante James of Aragon, firstborn son and heir of James II.

In the meeting of Calatayud of 1311 it was also agreed to resume the war against the Kingdom of Granada, but it was decided that each Kingdom should do it separately, while James II promised to mediate between Ferdinand IV and his father-in-law in the conflict that both maintained about the possession of some cities of which Denis of Portugal had taken over during Ferdinand IV's minority.
However, the death of Ferdinand IV in September 1312 put an end to such negotiations between the sovereigns of Aragon and Portugal.
On 3 April 1312, shortly after the meeting of Calatayud, Juan Manuel of Villena married in the city of Xàtiva with the Infanta Constance of Aragon, another daughter of James II.
In mid-1311, John of Castile and the principal magnates of the Kingdom threatened Ferdinand IV by ceasing to serve him, if the monarch didn't satisfy their requests. John of Castile and his followers demanded that the King replace his advisers and privates for John of Castile himself, the Dowager Queen, Infante Peter, Juan Manuel of Villena, Juan Núñez II de Lara and the Bishops of Astorga, Zamora, Orense and Palencia. Juan Manuel of Villena remained loyal to Ferdinand IV, because on 15 October the King had given him all the royal pechos (tributes) and rights of Valdemoro and Rabrido, except for the moneda forera of both places and the martiniega (another tribute) de Rabrido, which had been granted to Alfonso de la Cerda.
With the desire to achieve peace in order to continue with the Reconquista, Ferdinand IV agreed to sign the Concord of Palencia on 28 October 1311 with John of Castile and the rest of the magnates, and whose clauses were ratified in the Cortes of Valladolid in 1312. The King promised to respect the customs, fueros and privileges of the nobles, prelates, and subjects of the towns, and not to try to deprived the nobles of the rents and lands that belonged to the Crown. Ferdinand IV ratified that the custody of his son, the Infante Alfonso, would be entrusted to his brother, Infante Peter, to whom also ceded the city of Santander. The King ceded to John of Castile the municipality of Ponferrada, with the condition that he didn't establish any type of alliance with Juan Núñez II de Lara, although he didn't fulfill his word before eight days of the signing of the Concord.
In December 1311 Ferdinand IV meet in Calatayud with James II of Aragon. At that moment was celebrated the marriage of Infante Peter of Castile and the Infanta Maria of Aragon, daughter of James II, although some authors indicate that the marriage was celebrated in January 1312. At the same time, Ferdinand IV gave to James II his eldest daughter, the Infanta Eleanor of Castille, to be raised in the Aragonese court until she had the proper age to marry the Infante James of Aragon, firstborn son and heir of James II.
In the meeting of Calatayud of 1311 it was also agreed to resume the war against the Kingdom of Granada, but it was decided that each Kingdom should do it separately, while James II promised to mediate between Ferdinand IV and his father-in-law in the conflict that both maintained about the possession of some cities of which Denis of Portugal had taken over during Ferdinand IV's minority. However, the death of Ferdinand IV in September 1312 put an end to such negotiations between the sovereigns of Aragon and Portugal. On 3 April 1312, shortly after the meeting of Calatayud, Juan Manuel of Villena married in the city of Xàtiva with the Infanta Constance of Aragon, another daughter of James II.
Ferdinand IV of Castile