Henry of Trastamara (1333? - 1379), was the illegitimate son of Alfonso XI of Castile and Leonora de Guzman, and half brother to Peter I of Castile. Became Henry II of Castile in 1366 when, as head of a host of soldiers of fortune, and with the aid of Bertrand du Guesclin[?], he drove Peter from his throne without giving battle. Henry murdered Peter in 1369. Married to Joan, daughter of John Manuel of Villena[?], head of a younger branch of the royal house of Castile. Their son was John I of Castile.
... common include:
1. A supporter of King Charles I of England during the English Civil War.
2. In the UK, a believer in the continued desirability of the royal family ...