In the 11th century, the brothers (and at least one sister) of two Norman families migrated to southern Italy. The initial group, the "Drengot" family, seems to have come because they were fleeing the punishment of one of the brothers, who had murdered a vice-count (Guillaume Repostel) at the court of Duke Robert of Normandy because the vice-count boasted of having seduced and dishonored Drengot's daughter. Different historians place the entry of these first Normans into southern Italy between 1017-1027, and they were recruited by a Lombard leader, Melo di Bari, to help with his revolution against the Byzantine empire.
As Charles Cawley writes, "The arrival of the Normans in southern Italy in the early 11th century triggered a complete change in the profile of the nobility. The new Norman rulers established their own network of counties and appointed their own followers as counts. There were numerous new appointments, and counts were frequently switched from one county to another, or dispossessed entirely as punishment for participation in the numerous rebellions organised against the Norman rulers. The information in the primary sources about these early Norman nobles is patchy. Despite access to many sources, it has proved difficult to reconstitute many of these noble Norman families for more than a couple of generations. Nor has much information been found on the precise origins of the Norman counts who settled in southern Italy. A few can be connected to noble families in Normandy, but these are the exception. It is assumed that the majority of Norman immigrants came from relatively humble backgrounds. In several cases, the sources hint at family connections between these newly established nobility and the Hauteville family of the dukes of Apulia/kings of Sicily, but not all such relationships can be traced precisely."