CHARLES IV. (1421-1461), king of Navarre, was. the son of John of Aragon, and of Blanche, daughter and heiress of Charles III., king of Navarre. On her death the-throne belonged to Charles, but his father retained it, and took as second wife the ambitious and unscrupulous Jeanne of Castile. Charles did not press his claim, but devoted himself to literature, until his step-mother roused him by repeated indiguities. He succeeded in having himself crowned, but soon after was defeated and imprisoned (1652). Next year he was released ; the struggle recom-menced, and he gained possession of a considerable part of Navarre. He was reconciled to his father, and recog-nized as king of Barcelona; but Jeanne caused him to be arrested and poisoned. He was a man of gentle disposition, and of considerable learning, He left a Spanish transla-tion of the Ethics of Aristotle, a chronicle of the kings of Navarre, and several poems.