Guillaume-Robert de La Marck (1563 - 11 January 1588) was a French Protestant prince, duke and military commander.
When the regency expired in 1584 he allowed Sedan to become a nucleus for Protestant forces in their conflict with the Catholic League, leading attacks against Guise at Daigny.
Lacking children, his titles and territories were inherited by his sister, who married Turenne thus ending the La Marck control of Bouillon and the Principality of Sedan.
[1][2] Bouillon played host to Navarre in 1574, who had fled to the principality of Sedan from court where he was a prisoner, in the final year of Henri-Robert's life.
[4] In the same year Bouillon decided to leave his territory under the regency of his sister and go on the offensive against the ligue, entering Alsace at the head of a mercenary army.