Robert established a regency council in Flanders and followed the retinue Godfrey of Bouillon, Duke of Lower Lorraine.
Robert responded by supporting the revolt of the Commune of Cambrai against the emperor and his supporter, Bishop Gaulcher, and seized a number of castles.
Robert led an army against Meaux, but near the city he was fatally wounded, fell of his horse, and drowned in the Marne.
Here we are concerned only with their earlier history, which is put for convenience under this heading in order to separate the account of the period when they formed practically a single area for historical purposes from that of the time when Holland and Belgium became distinct administrative units.
It was precisely at this time that Flanders, and gradually the other feudal states of the Netherlands, by marriage, purchase, treachery or force, fell under the dominion of the house of Burgundy.
He inherited Flanders and Artois, purchased the county of Namur (1427) and compelled his cousin Jacqueline, the heiress of Holland, Zeeland, Hainault and Friesland, to surrender her possessions to him, 1428.