He served as a knight and military leader in Flanders and England before inheriting his family territories in France and the Low Countries.
The House of Bethune was one of the more influential families in Artois, which had been a Flemish fief until Flanders had to cede it to the French heir apparent Louis, the son of Isabella of Hainault.
In 1213, Robert accompanied Count Ferdinand into exile in England after King Philip II of France had invaded Flanders.
Later that year, he and the Earl of Salisbury led a successful attack on the French fleet in the port of Damme, thereby thwarting an impending invasion of England.
[1] This story was recorded by an anonymous chronicler, who was employed by Robert and who wrote between 1220 and 1223 a chronicle about the French kings entitled Chroniques des rois de France et ducs de Normandie[2] Daniel of Béthune died childless in 1226 and Robert inherited the family territories around Béthune, Richebourg, Warneton and Dendermonde, as well as the hereditary post of advocatus of Abbey of St. Vaast near Arras.
A junior line of the House of Béthune, descended from Robert's younger brother Guillaume III (d. 1243), survives to this day as Lords of Meulebeke.