Pedro, king of Castile and Leon, often known to posterity as 'the Cruel', was born in 1334 as the only son of Alfonso XI (1311-50, betrothed to Edward II's daughter Eleanor of Woodstock in 1324) and Maria of Portugal (1313-57). Pedro was set to marry Edward III's second daughter Joan of Woodstock (b. c. January 1334) in the summer of 1348, but she died of the plague on her way to their wedding, and five years later, by now king of Castile and Leon, Pedro married the French noblewoman Blanche de Bourbon instead. Pedro's love life was exceedingly complicated. By the time of his wedding to Blanche, he was involved in an intense relationship with the Castilian noblewoman Doña María de Padilla, who gave birth to their eldest child, Beatriz, some months before Pedro married Blanche in June 1353. He abandoned the unfortunate Blanche within days of their wedding and went off with María, who gave birth to their second child, Costanza, later duchess of Lancaster and Edward III's daughter-in-law, in July 1354 thirteen months after Costanza's father married another woman.
In April 1354 three months before Costanza was born, however, Pedro claimed to have had his marriage to Blanche de Bourbon annulled and went through a wedding ceremony with another Castilian noblewoman, Doña Juana de Castro. (Didn't I say his love life was insanely complicated? There's that whole thing about him fathering a child called Fernando with María de Padilla's first cousin María González de Henestrosa as well.) The king made a habit of abandoning women just after he married them, and left Juana de Castro - whose sister or half-sister Inês was the famous assassinated mistress and perhaps wife of Pedro's uncle the king of Portugal - the day after their wedding. Their extremely brief relationship resulted in a son, Juan, born nine months later in early January 1355, more or less on the same day as his aunt Inês de Castro's assassination. Juan was six months younger than his half-sister Costanza, and a few months older than his half-sister Isabel, duchess of York and also Edward III's daughter-in-law, the third child of King Pedro and María de Padilla, who was born in the summer or autumn of 1355. Pedro and María's fourth and youngest child, Alfonso, was born in 1359, and María de Padilla and the tragic Blanche de Bourbon both died in 1361, Blanche after eight years of captivity.
Below: baths in the Alcázar in Seville, named after María de Padilla (my pics, taken during a visit to Seville a few years ago).
Pedro and María's son Alfonso died in Seville on or about 18 October 1362, aged just three (Fernando, Pedro's young son from his relationship with María's cousin, also died in 1361 or 1362). A month later on 18 November 1362, King Pedro made his will, in medieval Castilian. It's printed in volume 1 of Pero López de Ayala's Crónicas de los Reyes de Castilla: Don Pedro, Don Enrique II, Don Juan I, Don Enrique III, published in 1779. (Ayala lived from 1332 to 1407, and his niece Teresa de Ayala, one of King Pedro's mistresses in the 1360s after the death of María de Padilla, bore him a daughter, María de Ayala, in c. 1367.) In his will, King Pedro expressed his wish for his kingdoms of Castile and Leon to pass to his and the late María de Padilla's eldest child Beatriz, and stated that Beatriz was to marry Fernando of Portugal (b. 1345), son and heir of Pedro's namesake maternal uncle the king of Portugal (d. 1367). Beatriz, in fact, died sometime after September 1366, when she and her younger sisters Costanza and Isabel were sent as hostages to Edward of Woodstock, prince of Wales and Aquitaine. The date of her death was not recorded, but she was almost certainly already dead when her father was stabbed to death by his illegitimate half-brother Enrique of Trastámara in March 1369, and was certainly dead by the time John of Gaunt married her younger sister Costanza in September 1371. Beatriz's fate is rather obscure. Some modern writers claim she became a nun at the convent of Santa Clara de Tordesillas, though I'm not sure how and when she could have, given that she was Pedro's eldest daughter and heir and he wished her to become queen-regnant of Castile and queen-consort of Portugal, and given that she was one of tres filiae nostrae or 'our three daughters' whom Pedro sent as hostages to Edward III's eldest son on or just after 23 September 1366. [Foedera 1361-77, pp. 805-6]
After Beatriz, Pedro left his kingdoms to his second daughter Costanza, then to his third daughter Isabel, then to his and Juana de Castro's son Juan. In later decades, Isabel and her husband Edmund of Langley (d. 1402), first duke of York, and their son and heir Edward (d. 1415), second duke of York, claimed the throne of Castile by right of male descent. They stated that as Costanza had only a daughter, Catalina of Lancaster, and no son, the Yorks had a superior right to Pedro's throne, because Pedro had specified that Castile and Leon would pass to Beatriz and her male heirs, then Costanza and her male heirs, then Isabel and her male heirs. In fact, they were wrong: Pedro's will stated that Beatriz was his primary heir and that a legitimate son of Beatriz would be next in line, or failing a son, her legitimate daughter. Beatriz was followed by Costanza in the succession if Beatriz had no legitimate sons or daughters (as indeed she did not), followed by Isabel if neither Beatriz nor Costanza had legitimate sons or daughters.
Pedro made a point of specifying that the sons, preferentially, or the daughters, failing the birth of sons, of his three daughters could inherit his kingdom. He did not specify any future husbands for Costanza and Isabel, though did state that his kingdoms would belong, in the event of Beatriz's death, to Costanza and whoever she married, succeeded by her son or daughter (mándo que herede los mis Regnos la Infant Doña Costanza mi fija é el que con ella casáre, é despues della el fijo ó fija). Pedro strictly ordered his three daughters never to marry into the Trastámara branch of the family, i.e. the descendants of his father Alfonso XI and his mistress Leonor de Guzmán, in particular the families of Pedro's oldest half-brother and future usurper and killer Enrique and Enrique's brothers Tello and Sancho. If they did, the girls would be cursed by God and by Pedro himself. Another man on Pedro's list of unmarriageables was his cousin Fernando of Aragon, el Infant Don Ferrando de Aragon, who joined the Trastámara brothers' rebellion against him. Pedro's granddaughter Catalina of Lancaster (b. 1372/73), Costanza's only surviving child and heir, married Enrique of Trastámara's grandson Enrique (b. 1379) in 1388, and they suceeded as king and queen of Castile in 1390. Although Pedro had not specifically stated that his daughters' children should not marry a Trastámara, I can't help wondering if the marriage gave Costanza some anxious moments, wondering if she was risking the wrath of God and her late father.
In his will, Pedro left a sizeable number of items to nine-year-old Beatriz, eight-year-old Costanza and seven-year-old Isabel and to their seven-year-old half-brother Juan, though whether the four ever received any of the bequests, given Pedro's downfall and his assassination by his half-brother Enrique of Trastámara in 1369, is another question. To Costanza, Pedro left 100,000 Moroccan gold coins, a large number of seed pearls, a gold cup, a crown which had once belonged to his father Alfonso XI, another crown decorated with eagles which had once belonged to his aunt Leonor, queen of Aragon (d. 1359), and a third crown which Pedro had had made in Seville. This last crown was set with a large balas ruby which had once been in the possession of Abu Abdullah Muhammad VI, emir of Granada, whom Pedro and other Christians called King Bermejo (meaning 'russet' or 'red'). Pero López de Ayala's chronicle says that in April 1362, Pedro invited the emir and thirty-six members of his entourage to Seville, where, after dining with them, he had them killed and stripped of their valuables. If this tale is true, the valuables perhaps included the large ruby which Pedro willed to Costanza seven months later. Pedro bequeathed far more of his possessions to Costanza than to her sisters Beatriz and Isabel or to Juan, perhaps indicating that she was his favourite child.
To Isabel, Pedro left 70,000 Moroccan coins, silk cloths, cloth-of-gold, rugs, unspecified 'other cloths' and a 'French crown' which had belonged to his tragic wife Blanche de Bourbon, whom Pedro refused to acknowledge as his wife and queen in the will and called simply 'Doña Blanca, daughter of the duke of Bourbon' (la corona Francesa que fué de Doña Blanca fija del duc de Borbon). He repeatedly referred to his long-term mistress and the great love of his life, María de Padilla, as 'the queen, Doña María, my wife'. María's jewels and other goods were to be divided into six portions; Beatriz (la Infant Doña Beatris) was to receive three of them, Costanza two, and Isabel one. Pedro's own personal goods which he had not bequeathed elsewhere in the will were to be divided into eight portions: three each for Beatriz and Costanza, and one each for Isabel and Juan. Beatriz was also to receive other items from her father, including a gold cup and another very large balas ruby which had belonged to Abu Abdullah Muhammad VI.
Finally, Juan (Don Juan mio fijo é de Doña Juana de Castro) was bequeathed his father's armour and weapons, including six swords and a basinet helmet. Juan, incidentally, was imprisoned for many years by his Trastámara cousins, as were his half-brothers Sancho and Diego, born in 1363 and c. 1365 as the children of King Pedro and his mistress Isabel de Sandoval. At an unknown date in the late 1300s or beginning of the 1400s, Juan married Elvira de Eril, daughter of his warder Beltrán, and they had two children who lived into adulthood and joined the Church. Juan and Elvira named their daughter Costanza, perhaps in honour of his half-sister the duchess of Lancaster, and she became prioress of Santo Domingo el Real in Toledo and died in 1478, while their son Pedro (d. 1461) was bishop of Osma and Palencia. Juan died in 1405.