[1] In 1282, he succeeded as the Count of Dreux, Braine, Montfort-l'Amaury, and Joigny, and as Seigneur of Montpensier, St. Valery, Gamaches, d'Ault, and Dommart.
[1] Robert fought with Philip IV of France in his wars in Flanders, including the sieges of Veurne, Cassel, de Bergues and Lille in 1297.
He was at the Battle of the Golden Spurs (fought near Cambrai), where the French forces under Robert II of Artois suffered an unexpected defeat.
He was chosen as one of the French ambassadors who negotiated an end to the war.
[1] Having outlived Jeanne, John then married Perrenelle of Sully (d. after 9 January 1331) in 1308.