The Navarrese Civil War of 1451–1455 pitted John II of the Kingdom of Navarre against his son and heir-apparent, Charles IV.
When Blanche died in 1441, John retained the government of her lands and dispossessed his own eldest son, Charles (born 1421), who had already been made Prince of Viana by his grandfather Charles III of Navarre in 1423.
[2] Charles was defeated at the Battle of Aybar in 1452, captured, and released;[3] and John tried to disinherit him by illegally naming his daughter Eleanor, who was married to Gaston IV of Foix, his successor.
In 1451, John's new wife, Juana Enríquez, gave birth to a son, Ferdinand.
In 1452, Charles fled his father first to France, where he vainly sought allies, and later to the court of his uncle, John's elder brother, Alfonso V of Aragon at Naples.