Sebastien,_Duke_of_Penthièvre
Sébastien de Luxembourg
French military officer, peer of France and governor of Brittany
Sébastien de Luxembourg, vicomte de Martigues (1530-1569) was a French military officer, peer of France and governor of Brittany. Martigues began his political career serving under his uncle Étampes the governor of Brittany as the lieutenant-general of the province. He gained the office of colonel-general of the French infantry after the prior office holder died at the siege of Rouen during the first war of religion. In this important military role he played a key part in the royal victory at the Battle of Dreux, the main battle of the first of the French Wars of Religion. In 1565 on the death of his uncle, he gained both the governorship of Brittany and the county of Penthièvre which was subsequently elevated to a dukedom.
During the second civil war he assisted the royal army in reaching full strength to hunt down the rebel army that was fleeing eastwards, before the abrupt peace restored the status quo in March 1568. Unhappy with the peace Martigues was among those campaigning for the crown to break off from the terms and renew hostilities, and he played a part in the opening campaign of the third civil war that September. Having participated at the crushing royal victory of Moncontour he was killed in the subsequent siege of Saint-Jean-d'Angély on 19 November 1569.