His introduction to military life came as he was made a knight in a conflict between his father and the Bishop of Metz. He then served Ferry III of Lorraine. He was preparing to go on crusade when his father died.
In 1284 Jeanne de Navarre, countess of Champagne, had married the future Philip IV of France, making the county of Bar adjacent to the French royal domain. Henry's reaction was a marriage to Eleanor, daughter of Edward I of England. When war broke out in short order between France and England, Henry was drawn in. The fighting ceased after the 1301 Treaty of Bruges. Under its terms, Henry gave up some fortresses and paid homage to Philip for part of his lands, then called the Barrois mouvant. He also undertook to fight in Cyprus against the Muslim forces.