The Castle of Belmonte (Spain), built by Juan Pacheco.
Juan Pacheco (1419 – 1474), 1st Marquis of Villena, was one of the most powerful and ambitious nobles in 15th-century Castile. As a close advisor to King Henry IV (Henry the Impotent), he held great influence at court. However, his shifting loyalties and political maneuvers helped create the conflict that led to the Castilian Succession Crisis. By switching sides multiple times, Pacheco played a key role in shaping the fight for the throne.
At first, Pacheco was one of Henry IV’s most trusted allies. He gained large amounts of land and power, including the lordship of Belmonte, where he built the Castle of Belmonte in 1456. But when other nobles, like Beltrán de la Cueva, started to gain the king’s favor, Pacheco felt threatened and turned against Henry IV.
In 1465, he joined a group of nobles who wanted to remove the king, arguing that Henry was weak and unfit to rule. They staged the Farce of Ávila, a public event where they symbolically deposed the king and declared his half-brother, Prince Alfonso, the rightful ruler. Pacheco became one of Alfonso’s main advisors and military leaders, but when Alfonso died suddenly in 1468, Pacheco had to find a new way to stay in power.
He then switched his support to Isabella, Henry IV’s half-sister, helping to negotiate the Treaty of the Bulls of Guisando (1468), where Henry named her as his heir. However, Pacheco wanted to control Isabella’s decisions. When she secretly married Ferdinand of Aragon in 1469 against his wishes, he saw her as a threat and once again changed sides. He returned to Henry IV’s camp and supported Joanna la Beltraneja, Henry’s daughter, as the rightful heir.
Pacheco’s constant shifting between rival factions deepened the crisis and helped lead to the War of the Castilian Succession (1475–1479). However, he did not live to see the war begin, as he died in 1474. Though his political plans ultimately failed, his influence left a lasting mark on Castile, and his Castle of Belmonte still stands as a reminder of his wealth and ambition.
