The sources do not agree concerning whether he was older[1] or younger than his brother Guy.
[5] Robert accompanied his elder brother Roger Borsa in 1086, when the latter went to Palermo to confirm his possessions in the County of Sicily.
He signed as a witness the document issued by Roger granting to the abbey of La Cava the monastery of the Holy Spirit in Bari.
[5] Felicia, unnamed, is described as "a lady of the highest nobility, daughter of King Robert Guiscard of Apulia" in the 14th-century Chronicon Pictum.
[5] He connects the younger Robert Guiscard and the queen's entourage to the Hungarian kindred of Oliver and Ratold, which the Chronicon claims originated in Caserta.