General Notes

Peter the Cruel (Spanish Pedro el cruel) (1334-69), king of Castile and León
(1350-69), the son of King Alfonso XI, born in Burgos. Peter owes his
sobriquet "the Cruel" to his ready use of murder and execution to eliminate
his political opponents, including, reportedly, several of his ambitious
half brothers. His principal conflict was with his older half brother, Henry
of Trastamara, who also claimed the throne. Henry enlisted the aid of King
Charles V of France, who in 1365 sent troops through Spain under the command
of Bertrand Du Guesclin. Overthrown, Peter left the country and requested
aid from Edward III of England, at that time engaged in fighting the Hundred
Years' War with France; Edward sent an army commanded by his son Edward,
prince of Wales, known as the Black Prince. The forces of Peter and Edward
defeated those of Henry, the French, and other allies at the Battle of
NÏjera in 1367, and Henry fled to France. Political differences between
Peter and Edward resulted in the latter's withdrawal from Spain with his
army. Henry then hastened back and with Du Guesclin's help engaged Peter and
his supporters in a civil war. Peter was defeated and killed at Campo de
Montiel in 1369; Henry assumed the throne as King Henry II.