The Normans first became familiar with southern Italy because of the pilgrimages they made to the Holy Land via the ports of Bari and Brindisi in southern Italy on ships bound for the Levant. In 1016, a Lombard leader, seeking independence from Byzantium, which then controlled Italy, invited a group of Norman knights to join his cause. Among them were the sons of Tancred de Hauteville (908-1041), including William (1009?-1046), the oldest, and Robert (1015-1085), later known as the “Guiscard,” or wily one.

Meanwhile, civil war had broken out between the Sicilian Arabs. Seeing a chance to make the island an imperial province once again, the Byzantine emperor entered into an agreement with the Normans and Lombards, who were then raising havoc across southern Italy and shipped them off to fight the Arabs. This army, which included other Italians and Greeks, landed in Sicily in 1038 and made rapid progress until the Greek general, George Maniakes (d. 1045), was recalled. The campaign then foundered, and the Normans returned to Italy.

Two decades later, they had grown into such a force that Pope Nicholas (990?-1061) raised an army against them. The Normans defeated the Papal forces at Civitate in 1053. However, in 1059, the Pope and Robert Guiscard came to an agreement by which the Pontiff conferred the title of Duke of Apulia, Calabria, and Sicily on the Norman knight.

Byzantine Mosaic, La Martorana Church, Palermo