Robert married Williswinda, daughter of Adalhelm, Grundherr im Wormsgau. Robert and Williswinda had three children:
Upon his death in 748, Robert was succeeded as count by his brother-in-law Signramnus, probably prior to his son Cancor coming of age.
In a charter of 741/2 which exists in several versions, wherein a Robert, son of Lambert, Count or Duke of the "pago Hasbaniensi et Masuarinsi", the land of Hasbanians and Masuarians, granted lands near Diest to Sint-Truiden Abbey.
The third continuation of the Gesta Abbatum Trudonensium, in its report of the charter, describes Robert as Robertus comes vel dux Hasbanie ("count or Duke of Hasbania").
This Robert, the Gesta says, is also the one mentioned as a Duke in the medieval biography (Vita) of Bishop Eucherius of Orléans. When Charles Martel exiled Eucherius to Cologne this was under the custody of the said Duke Robert of Hasbania (Hasbanio Chrodoberto duce).