This chapter discusses the brief chronological overview of the history of the Normans in southern Italy. For the theme of the chapter the Graeco-Byzantine heritage in the Norman kingdom, four elements are particularly relevant. First, the conquest was a private military affair. Second, although several areas of southern Italy were inhabited by a substantial Greek population during the eleventh century Cilento and southern Basilicata, and particularly Salento in the demographic context of the Norman duchy they constituted a minority. Third, that the Norman rulers were vassals to the pope implied that they were obliged to return the Greek bishoprics of Calabria, Sicily and the Salento, to the ecclesiastical jurisdiction of Rome. Fourth, the Norman Kingdom of Sicily was created by Roger II, the heir of the first count of Calabria and Sicily, who had grown up in a court largely dominated by Greek administrators, and whose chief advisors were apparently Greek.