Fadrique was a twin to Henry of Trastámara. While his father lived, the children of Eleanor profited from appointments and royal grants. With this backing, in 1342, Fadrique rose to the leading role of Maestre of the militant monastic Order of Santiago. The prior Maestre had been Alonso Meléndez de Guzmán, his maternal uncle. When Alfonso XI died suddenly in a siege of Gibraltar, attempts were made by his half brother King Pedro I, his mother, and her court favorite, the Duke of Albuquerque to dispossess the entire family of Eleanor. This and the subsequent execution of Eleanor in Talavera in 1351, led to rebellion by Eleanor's sons, Henry, future Henry II of Castile, Fadrique, Tello of Castile, and Sancho of Castile, Count of Alburquerque. Each rebelled from their independent corners of the Spanish kingdom. Through a combination of threats and diplomacy, Peter I of Castile was able to elicit fealty and a temporary reconciliation with his half-brothers. But this was not to last. Fadrique was named royal emissary to France, where he went to escort Pedro's bride, Blanche of Bourbon. The subsequent turmoil of this marriage and Pedro's entanglement with his mistress, María de Padilla, was unlikely to have help cement a relationship between Pedro and Fadrique. In 1354, Fadrique was granted the role as custodian of the Portuguese frontier. Here, along with his brother Henry, they again began to plot rebellion, entering in negotiations with Juan Alfonso de Alburquerque, formerly a foe and the favorite of Pedro's court, but now fallen from favor with the king. Henry ultimately also went to seek support from the French monarchy. A second rebellion was launched against Pedro, this time others joined including the city ofToledo, who requested help from Fadrique. He arrived with 700 soldiers. Again Pedro cajoled with a mixture of forgiveness and with the mediation of Juan Fernández de Henestrosa, uncle of María de Padilla, and for a second time Fadrique was reconciled to Pedro and offered a post with the court. Pedro even invited Fadrique to Seville, with the pretext of seeking his council. The subsequent events were chronicled most famously by Pero Lopez de Ayala, a contemporary historian, but one who ultimately worked under the victorious Henry II, the full brother of Fadrique. Some later historians found the characterization of Pedro as a cruel murderer as propaganda. Once in Seville, Fadrique and his knights met with the king. Paying visits to the King's mistress, he apprehended the threatened treachery, and rushed to the stables at the Alcázar of Seville. Soldiers of the king separated Fadrique from his knight companions, and in a courtyard of the Alcazar, he was murdered with a mace hit from behind. Ayala claims the King asked for his lunch to be brought to him there, so that he could dine in front of the moribund Fadrique. Other stories hold that he was captured and ultimately directly executed by the king. After his murder, his body was interred in the Cathedral of Seville. In 1579, his mortal remains were transferred to the crypt of the royal chapel where they remain to this day.
Descendants
As Maester of the Order of Santiago, Fadrique was putatively required to remain celibate. Through illegitimate marriages he fathered the lineage of the Enríquez family, who became Admirals of Castile and later Dukes of Medina de Rioseco. By an unknown woman, he had one illegitimate son:
