Guise took an active military role in the second and third wars of the
French Wars of Religion, fighting at the
Battle of Saint-Denis in 1567, the
Battle of Jarnac in 1569, and successfully defending
Poitiers during a siege by Admiral Coligny. He was wounded at the
Battle of Moncontour. In 1570 the third war of religion was brought to an end with the
Peace of Saint-Germain-en-Laye, part of which stipulated a marriage between the Protestant
king of Navarre (future king Henry IV) and the King's sister
Margaret of Valois as a means of ensuring stability. Around this time Guise began a romance with the King's sister, apparently with pretensions to her hand in marriage, which quickly became known around court. Upon discovering this, Margaret's brothers
Charles IX and the
duke of Anjou, were furious, assaulting Margaret in anger. While some suggested Guise be punished with assassination, it was settled on banishing him from court for his indiscretions. On 3 October he married
Catherine of Cleves, thus assuming the title of
Count of Eu from her inheritance. The August 1572 marriage between the king of Navarre and Margaret necessitated the presence of the majority of the Protestant leadership in Paris. Shortly after the wedding, Coligny, who had made a rare visit to the capital for the occasion, was shot in the shoulder in an attempted assassination. Guise was a chief suspect of having ordered the attempt, due to his long running feud. As the situation in Paris deteriorated over the next several days, the royal council planned and executed a targeted elimination of the Protestant leadership in Paris, which would spiral into the
St. Bartholomew's Day massacre. During the massacre Guise would oversee the murder of Coligny, and attempted but failed to capture several other targets, but was displeased at the situation descending into a general massacre, shielding fleeing Protestants in his residence. When the wars of religion subsequently resumed Guise was wounded at the
Battle of Dormans, and was thereafter known, like his father, as . With a charismatic and brilliant public reputation, he rose to heroic stature among the militant
Catholic population of France as an opponent of the
Huguenots. == Catholic League ==