The Normans were devout Christians but they have played an important role in weakening the Byzantine Empire. In the early eleventh century, the first Norman groups migrated as pilgrims and mercenaries from France to Italy. Some of these Norman groups managed to distinguish themselves as fearsome warriors and the Christian rulers of southern Italy started using them as mercenary soldiers. Eventually these groups began to create their own fiefdoms in several places and started seeing themselves as free people.
The first major battle that the Normans fought in southern Italy was the Battle of Civitate in June 1053. They were pitted against the combined forces of the Pope and the Holy Roman Empire. The Normans destroyed the papal army, and captured Pope Leo IX. The Normans kept the Pope in honorable captivity to force him to acknowledge their conquest of Calabria and Apulia. In March 1054, the Pope acknowledged the Norman conquests and he was allowed to go. He did not live long after his return and died on 19 April 1054.
After the Battle of Civitate, Normans became a major power in southern Italy. Robert Gusicard rose to prominence as their leader. Between 1057 and 1059, he became the count of Apulia and Calabria. He was a charismatic leader and he united the Norman factions into a powerful army which could vanquish the Lombard Princes and Byzantine governors. From 1059 to 1085, he was the Duke of Apulia and Calabria and Duke of Sicily.
In her work of history, the Alexiad, Anna Komnene says that Guiscard left Normandy with five mounted riders and thirty followers on foot. After his arrival in Langobardia in 1047, he initially operated as the chief of a roving robber-band. She leaves the following description of Guiscard:
“This Robert was Norman by birth, of obscure origins, with an overbearing character and a thoroughly villainous mind; he was a brave fighter, very cunning in his assaults on the wealth and power of great men; in achieving his aims absolutely inexorable, diverting criticism by incontrovertible argument. He was a man of immense stature, surpassing even the biggest men; he had a ruddy complexion, fair hair, broad shoulders, eyes that all but shot out sparks of fire. In a well-built man one looks for breadth here and slimness there; in him all was admirably well-proportioned and elegant... Homer remarked of Achilles that when he shouted his hearers had the impression of a multitude in uproar, but Robert’s bellow, so they say, put tens of thousands to flight.”
Gusicard began his Sicilian campaigns in 1060. By 1072, he had captured most of Sicily. With the capture of Bari in 1071, he had wiped out all traces of the Byzantine Empire in southern Italy. He fought with the Byzantine Emperor Alexius I Comnenus in October 1081, at the Battle of Dyrrhachium. Alexius was defeated, and Gusicard took possession of Corfu and Durazzo. He sacked the town of Cannae, but left the Cathedral and the Bishop’s house unharmed.
In June 1083, King of Germany Henry IV besieged Pope Gregory VII in Castel Sant’Angelo. On an earlier occasion, Gregory VII had excommunicated Gusicard for encroaching on papal land, but Gusicard came to the aid of the besieged pope. In March 1084, he marched into Rome with an army of 36,000 soldiers. Henry IV was forced to retreat from Rome. Gusicard’s army sacked the city for three days, and after that he escorted Gregory VII to the papal seat in Rome.
The Normans were responsible for the Great Schism between Latin and Orthodox Christianity. In 1054, before he was captured by the Normans, Pope Leo IX had sent a papal delegation to Constantinople to negotiate an alliance with Emperor Constantine IX Monomachos, in view of the Norman attacks in Italy. Monomachos was a weak emperor. He could not decide what action could be taken against the Normans. This led the Pope and the Patriarch of Constantinople to mutually excommunicate each other, and the Great Schism of 1054 was born.
Gusicard died in 1085, and was succeeded by Roger Borsa, his son by Sichelgaita. His other son Bohemond, by an earlier wife Alberada De Macon, became the legendary figure of the First Crusade. Bohemond tried to fulfill his father’s dream of conquering the Byzantine Empire, but he was defeated in 1108 by a coalition force of the Venetians and Byzantine Emperor Alexius I Comnenus in the battle at Epirus, in south-western Balkans.