Henry II of CASTILE, 1st Count of Trastámara, also known as Henry of Trastámara. He was King of Castile and Leon from 13 March 1366 – 3 April 1367.
"Henry was the fourth of ten illegitimate children of King Alfonso XI of Castile and Eleanor de Guzmán, a great-granddaughter of Alfonso IX of León. He was born a twin to Fadrique Alfonso, Lord of Haro, and was the first boy born to the couple that survived to adulthood.
"At birth, he was adopted by Rodrigo Álvarez de las Asturias. Rodrigo died the following year and Henry inherited his lordship of Noreña. His father later made him Count of Trastámara and lord over Lemos and Sarria in Galicia, and the towns of Cabrera and Ribera, which constituted a large and important heritage in the northeast of the peninsula. It made him the head of the new Trastámara dynasty, arising from the main branch of Burgundy-Ivrea.
"While Alfonso XI lived, his lover Eleanor gave a great many titles and privileges to their sons. This caused discontent among many of the noblemen and in particular the queen, Maria of Portugal, and her son, Pedro, known as Pedro the Cruel and the Just." 
On 27 July 1350, Henry married Juana Manuel, the daughter of Juan Manuel, Prince of Villena, head of a younger branch of the royal house of Castile. They had three children:
John I (1358–1390)
Eleanor (1361–1425), wife of Charles III of Navarre
Joanna (1367–1374), died young
He also had several children outside wedlock, some of which he mentioned in his will dated 29 May 1374.
Alfonso Enriquez, Count of Gijón and Noreña (1355 – c. 1400), a son of Elvira Íñiguez, Count of Noreña and Gijón. He married Isabel of Portugal, Lady of Viseu.
Leonor de Castilla, daughter of Leonor Álvarez, from Dueñas, Palencia.
Juana de Castilla (1367–¿?), daughter of Elvira Íñiguez. Her father mentioned her in his will, and said that if she did not marry Pedro de Aragón then she would inherit Urueña. Pedro was the Marquis of Villena (1362—Aljubarrota, 1385) and son of Alfonso de Aragón y Foix.
Constanza Enríquez de Castilla. Her father did not mention her mother's name. When he wrote the will in 1374, she was engaged to Infante Denis, Lord of Cifuentes (1354–1397). However she eventually married his brother, Infante John, Duke of Valencia de Campos (1349–1387). She inherited Alba de Tormes. She is also the protagonist of the 2015 historical fiction novel, La Bastarda, the first book in The Trastámara Series by author K.M. Guerin.
Fernando Enríquez de Castilla (1365–1438). His father describes him as the son of Beatriz Fernández.
María de Castilla (1375-c.1393), daughter of Beatriz Fernández. She married Diego Hurtado de Mendoza (Admiral of Castile), Lord of Mendoza, and Mayordomo mayor of King John II of Castile.
Fadrique de Castilla (1360–1394), son of Beatriz Ponce de León y Jérica. Named Duke of Benavente by his father, he died in prison in Almodóvar del Río in 1394. He married Leonor Sánchez de Castilla, illegitimate daughter of Sancho Alfonso, 1st Count of Alburquerque.
Beatriz de Castilla (?-1409), daughter of Beatriz Ponce de León y Jérica and Lady of Niebla. She married Juan Alonso de Guzmán in 1370 or 1371. He was Lord of Sanlúcar de Barrameda and the first Count of Niebla. Later he became a monk in the San Clement Monastery in Seville, where he was buried.
Enrique de Castilla (1378–1404), son of the Cordoban Lady Juana de Sousa, daughter of Vasco Alfonso de Sousa, the mayor of Córdoba, with María Gómez Carrillo, the Duchess of Medina Sidonia and Countess of Cabra. Enrique is buried in the Cathedral of Córdoba.
Pedro Enríquez de Castilla (?-1366). He is buried in Segovia Cathedral.
Isabel Enríquez de Castilla (?-c.1419), daughter of Juana de Cárcamo. She married Gonzalo Núñez de Guzmán, however, this marriage was dissolved by Pope Clemente VII. Later she entered the monastery of Santa Clara la Real de Toledo where she became its abbess and was buried.
Inés Enríquez de Castilla (?-c.1443), daughter of Juana de Cárcamo, also an abbess of the monastery at Santa Clara la Real de Toledo where she was buried.
Juana Enríquez de Castilla, daughter de Juana, Lady of Cifuentes and wife of Infante Denis, Lord of Cifuentes (1354–1397), son of Peter I of Portugal and Inês de Castro, she is buried at Santa María de Guadalupe
Arco y Garay, Ricardo del (1954). Instituto Jerónimo Zurita. Consejo Superior de Investigaciones Científicas. (ed.). Sepulcros de la Casa Real de Castilla [Tombs of the Castilian Royal Family] (in Spanish) (1st ed.). Madrid. OCLC 11366237.
Elorza, Juan C.; Lourdes Vaquero; Belén Castillo; Marta Negro (1990). Junta de Castilla y León. Consejería de Cultura y Bienestar Social (ed.). El Panteón Real de las Huelgas de Burgos. Los enterramientos de los reyes de León y de Castilla [The Royal Pantheon of the Huelgas de Burgos. The graves of the monarchs of León and Castile] (in Spanish) (2nd ed.). Editorial Evergráficas S.A. ISBN 84-241-9999-5.
López de Ayala, Pedro (1994–1997). Buenos Aires (ed.). Crónica del rey don Pedro y del rey don Enrique, su hermano, hijos del rey don Alfonso Onceno [A chronicle of the kings Peter and Henry, his brother, sons of the king Alfonso Onceno] (in Spanish). OCLC 489686613. (critical edition and notes by Germán Orduna; a preliminary study by Germán Orduna and José Luis Moure)
Valdeón Baruque, Julio (1996). Palencia. Diputación Provincial de Palencia (ed.). Enrique II. ISBN 84-8173-051-3.
Todesca, James, ed. (2015). The Emergence of León-Castile c.1065-1500: Essays Presented to J.F. O'Callaghan. Ashgate Publishing Limited.