(April 5 1604
– September 18 1675
) was Duke of Lorraine
from 1624 to 1634, when he abdicated under French pressure in favor of his younger brother, and again from 1661 until 1675. He came to loose his duchy because of his notionally anti-French policy for in 1633, French troops invaded Lorraine
in retaliation for Charles's support of Monsieur Gaston
—who repeatedly plotted against Richelieu's governance of France under the childless Louis XIII
and treated dangerously with its enemies as a young heir apparent
—and Richelieu's policies were always anti-Habsburg so as to increase the strength and prestige of France at the expense of the two dynasties. Gaston d'Orléans, frequently sided with either branch of the Habsburg family against Richelieu, who was de facto
ruler of France as its Chief Minister, and had to flee several times to avoid charges and trial for treason. His allies and confederates generally bore the price of these escapades by the young and impetuous heir and Charles IV was one such.
In that circumstance and sense, Charles was a casualty of the fierce factional infighting in the French court between the Kings' brother Gaston d'Orléans, and Cardinal Richelieu, even though technically, Lorraine was subject to the Holy Roman Empire and the Emperor Ferdinand II of Austria. Forced to make humiliating concessions to France, he abdicated under the French pressure and invasion in 1634 in favor of his brother and entered the imperial service in the Thirty Years' War.
In 1651 Charles IV was approached by an Irish delegation who were seeking his support to defend Ireland from the invasion of the Parliamentarian army of England. Although Charles was initialy interested in the proposal, it soon became apparent that it would be impossible to save Ireland from the conquest.
In 1670, the duchy was again occupied by the French under the Sun king, Louis XIV. He served in the Imperial armies in both the Thirty Years' War and the Franco-Dutch War (1672–1678), both of which added to the power of France.
In 1675 he defeated François de Créquy at Konzer Brucke, and died the same year in Austrian service.
The duchy was not restored to his family until more than twenty years later.
He is sometimes numbered as Charles III of Lorraine.