Sébastien, Duke of Penthièvre
Sebastien de Luxembourg, duke of Penthièvre was viscount of Martigues, count and later duke of Penthièvre and a peer of France.
He was the son of François de Luxembourg and Charlotte de Brosse, daughter of René de Brosse.
Nephew of Jean de Brosse, duc d'Étampes, he was allowed to inherit his uncle's taken estates and was subsequently created the 1st Duke of Penthièvre.
He participated at the Siege of Leith in 1560. He arrived in January and the Protestants captured two of his ships laden with supplies, and it was said he was so angry he tore his beard out - "he rent his hair from his beard so clean as though he had been new shaven." In April he joked that the English army had arrived only to besiege the village of Restalrig. He returned to France aboard the Primrose in July.
In 1556 he married Marie de Beaucaire de Puyguillon, a lady in waiting to Mary Queen of Scots. He asked the queen of Scots to be godmother to his daughter Marie in 1562 and she sent David Beaton of Melgund as her representative. His daughter and heiress Marie de Luxembourg married Philippe-Emmanuel de Lorraine, duc de Mercœur, the rebel in Brittany.
He was killed on 19 November 1569 at the Siege of Saint-Jean-d'Angely.