He married
Joan of France (
1343–1373), daughter of king
John II of France.
He was implicated in the assassination (
January 8, 1354) of the constable of France,
Charles de la Cerda. La Cerda was to be a beneficiary of the fiefdoms of Champagne, Brie, and Angoulême, of which it is believed, Charles the Bad felt he was entitled to through the ancestry of his mother, the Queen of Navarre. In reply, King John attacked Évreux and Navarre, but after Charles allied with the
Black Prince (son of
King Edward III of
England), the
Treaty of Mantes of
22 February 1354 returned the peace, Charles enlarging his possessions. This has to be renewed as the
Treaty of Valognes the next year and this, too, did not last. John captured and imprisoned Charles in
1356, but Charles was released after the
Battle of Poitiers. During certain stages of the
Hundred Years' War, he was allied with the English. He was one of the nobles involved in the repression of the
Jacquerie.
In
1361, after the premature death of his second cousin, Duke
Philip I of Burgundy, Charles claimed the
Duchy of Burgundy by
primogeniture. He was the grandson of Margaret of Burgundy, eldest daughter of Duke
Robert II of Burgundy (d.
1306). However, the duchy was taken by John II, son of
Joan of Burgundy, second daughter of Duke Robert II, who claimed it in
proximity of blood.
In
1364, he was defeated by
Bertrand du Guesclin, and driven from his Norman lands.