PETRO1. Pedro IV, King of Castile and Leon from 1350 to 1369, was known as Pedro the Cruel. His illegitimate brother, known as Henry the Bastard, instigated an insurrection against him, and Pedro sought aid from Edward, Prince of Wales, who was in Bordeaux at the time. Froissart says that the prince's advisers cautioned against aiding Pedro and gave as reasons the Pope's excommunication, his reputation for great pride, cruelty, and wickedness. It was generally rumored that Pedro murdered his young wife, the duke of Bourbon's daughter. The Prince of Wales, however, decided to help Pedro regain his throne. In 1365 Henry the Bastard appealed to the French king for help, and Charles sent him Bertrand du Guesclin, who helped establish the Bastard on the throne. In 1367 the Prince of Wales defeated Henry and Bertrand at Navarretta near Roncevalles. In 1369 Pedro again faced Henry and du Guesclin; this time he was defeated and captured, and his brother later killed Pedro with his own hand. Bertrand du Guesclin was made Constable of Spain; Charles made him Constable of France and Lord of Boucicault (Froissart I, 232-245).
The Monk tells Pedro's story in two stanzas, MkT 2375-2390. Chaucer may have learned of the manner of Pedro's death from several sources. In 1371, John of Gaunt married Constance of Castile, Pedro's daughter, and styled himself "King of Castile." Chaucer's wife Philippa was assigned to her household, and he may have learned the story from her. H.L. Savage suggests Fernando de Castro, a Spaniard at the English court, as a source. Haldeen Braddy thinks that Sir Guichard d'Angle, who had served with the Black Prince in the Castilian civil war, is a more likely source than de Castro. The fact that Philippa Chaucer served John of Gaunt's wife may account for Chaucer's laudatory stanzas on Don Pedro. A. Brusendorff suggests that a ballade on du Guesclin, attributed to Eustache Deschamps, may have given Chaucer further information; he points out certain verbal resemblances between Chaucer's story and the ballade. [Charles Olyver: Genylon-Olyver]
Petro occurs medially, MkT 2375.