Pacheco spent his early years in Belmonte before entering court life. The exact dates are uncertain but Pacheco's father probably sent him into the service of Constable
Álvaro de Luna around 1428. Sometime between 1435 and 1440, he joined the household of the heir apparent, Prince Enrique (the future Enrique IV). He promptly gained the prince’s confidence and established a relationship that was the foundation of his swift rise to prominence. Pacheco spent his early years in Belmonte before entering court life. The exact dates are uncertain but, Pacheco's father probably sent him into the service of Constable
Álvaro de Luna around 1428. Sometime between 1435 and 1440, he joined the household of the heir apparent, Prince Enrique (the future Enrique IV). He promptly gained the prince’s confidence and established a relationship that was the foundation of his rise to prominence. Pacheco’s success was furthered by strategic alliances and advantageous marriages. Initially wed to Angelina de Luna, a relative of the powerful royal favorite Álvaro de Luna, he later secured an annulment and married María Portocarrero, daughter of a prominent noble family with connections to the
Admiral of Castile. By the early 1440s, he had accumulated important court offices, including membership in the Royal Council and the position of Chief Chamberlain. His elevation culminated in 1445, following the
Battle of Olmedo, when he was granted the title of Marquis of Villena, which entailed vast territorial holdings in strategically important regions near the Aragonese frontier. This marked his definitive emergence as a major figure in Castilian politics. In the final years of John II's reign, Pacheco consolidated his power by acquiring additional offices and lands. He managed the prince’s revenues, served as Chief Magistrate of Castile, and expanded his domain through acquisitions such as
Villarrobledo. Pacheco exerted significant influence over Prince Henry, shaping his political decisions. This influence contributed to the growing estrangement between the prince and Álvaro de Luna. Pacheco encouraged Henry’s opposition to the royal favorite, whose downfall and execution in 1453 eliminated a major rival. Upon John II’s death in 1454 and Henry’s accession, Pacheco was widely recognized as the most influential nobleman in Castile. Despite his early dominance, Pacheco’s position at court proved unstable. Henry IV increasingly favored other courtiers, including Miguel Lucas de Iranzo, Juan de Valenzuela, and
Beltrán de la Cueva, whose rise diminished Pacheco’s influence. In response, Pacheco gradually distanced himself from the king and led the noble opposition. Unlike Álvaro de Luna, who sought to strengthen royal authority, Pacheco’s actions were driven by his own pursuit of power and wealth. Still, his political skill kept him central in Castilian affairs, sometimes eclipsing the king. Between 1455 and 1461, he joined military campaigns against the Emirate of Granada and controlled the machinery of government, gaining additional titles such as Count of Xiquena and Marquis of Los Vélez, and holding offices including Chief Justice of Segovia and Chief Magistrate of Asturias. As Henry IV relied more on new favorites, tensions with Pacheco grew. Although the marquis initially maintained a facade of loyalty, he began conspiring with other nobles dissatisfied with royal authority. His duplicity nearly led to his arrest in 1460, but he avoided capture and temporarily reconciled with the king. By the early 1460s, Pacheco had openly aligned with the nobility against Henry IV, ostensibly to counter Beltrán de la Cueva’s influence but more fundamentally as part of a broader struggle between aristocratic and royal power. In 1464, the noble faction led by Pacheco forced Henry IV to accept significant concessions, effectively imposing aristocratic control over the monarchy. When the king attempted to reassert his authority, the nobles responded with open rebellion. In 1465, they staged the symbolic deposition of Henry IV in what became known as the
Farce of Avila and proclaimed Henry's half-brother, Infante Alfonso, as king. Pacheco played a central role in this unprecedented act, which plunged Castile into civil war. Initially, the rebel faction enjoyed considerable success, controlling much of the kingdom. However, the conflict soon turned against them. The death of Pacheco’s brother, Pedro Girón, in 1466 deprived the rebels of an essential ally. For a time, Pacheco stepped away to assume responsibility for his brother’s estates and the guardianship of his nephews. During the turmoil of civil war, Pacheco seized the Grand Mastership of the
Order of Santiago. This was one of the most prestigious offices in Castile, bringing great wealth and authority. The administration of the Grand Mastership had belonged to the Infante Alfonso, but upon his proclamation as king at Avila, it became vacant, and Juan Pacheco seized the opportunity. In 1467, he orchestrated his selection by the electors of the Order. However, while he was preoccupied with the matter of the Mastership of Santiago, the
Second Battle of Olmedo took place in his absence. There, the royalists achieved a significant victory against the faction of Infante Alfonso. The Infante's sudden death in 1468 left the opposition without a clear leader. Following this loss, Pacheco attempted to rally support around the king’s half-sister, Isabella (later Isabella I), but she declined to be proclaimed queen, instead accepting recognition as heir apparent. The resulting compromise between Henry IV and the nobility was formalized in 1468 with the
Treaty of the Bulls of Guisando, which acknowledged Isabella as the king’s successor but required that she marry only with the king's consent. Pacheco subsequently reconciled with Henry IV and returned to royal service, once again seeking to dominate the government. During this period, he secured confirmation of his titles and estates, including the Marquisate of Villena and the Mastership of Santiago, and acquired additional possessions including the castle and town of Escalona, later elevated to a duchy. Pacheco’s political stance shifted again in 1469 when Isabella married
Ferdinand of Aragon without Henry IV's consent. Fearing that Ferdinand might reclaim the marquisate of Villena due to prior Aragonese ownership, Pacheco abandoned his support for Isabella and instead championed the cause of Henry IV’s daughter, Joanna. He sought to arrange her marriage to King
Afonso V of Portugal, hoping to secure his own territorial interests. In 1470, he successfully persuaded Henry IV to revoke Isabella’s status as heir and recognize Joanna instead. By this time, however, Pacheco’s health was deteriorating, and he began to make provisions for his death, including the establishment of entailed estates for his sons. In his final years, Pacheco continued to expand his holdings and influence. He remarried after the death of María Portocarrero in 1472 and secured additional grants, including the important town of Trujillo. Although resistance delayed his control of this territory, he eventually took possession of it shortly before his death. Juan Pacheco died on October 4, 1474, in Santa Cruz de la Sierra. His remains were initially interred in the Monastery of Guadalupe before being transferred to the Monastery of Santa María del Parral in Segovia, where he had established a family pantheon. ==Marriages and offspring==