In this article we shortly present how the Roman Empire lost control of several important cities situated in the Italian peninsula.
AMALFI. Seaport on the southwest coast of Italy between Naples and Salerno. Like Gaeta, Amalfi belonged nominally to the Byzantine duchy of Naples, but it constituted an independent merchant republic after 839 with close political, economic, and artistic ties to Byzantium, as the great Byzantine bronze doors of the cathedral of Amalfi illustrate. However, the occupation of Amalfi in 1073 by the Normans, as well as the increasing dependence of Byzantium on Venice, rapidly diminished those ties.
ANCONA. Italian port-city located on a promontory along the coast of the Adriatic Sea. Like Croton it remained in Byzantine hands during the long wars with the Ostrogoths during the reign of Justinian I, resisting a determined siege by Totila in 551. In the ninth century it became semi-independent, recognizing the nominal authority of the papacy. In 1155 Manuel I used Ancona as a base of operations against the Normans. Merchants from Ancona carried on an active trade with Byzantium. One such merchant, Cyriacus of Ancona, wrote an account of his travels throughout Byzantine lands from 1412 to 1454.
APULIA. The heel-shaped, southeastern part of the Italian Peninsula, bordered by the mountainous Garagano Peninsula in the north and the Strait of Otranto in the south. Bari and Brindisi were its chief towns. Apulia was a battleground between Justinian I’s troops and the Ostrogoths. The Lombards overran it in the late sixth century, making it part of the Duchy of Benevento. Subsequently it was attacked by Arabs, and by Louis II, but Basil I reconquered much of the region for Byzantium in the ninth century. In the 11th century, control shifted to the Normans under Robert Guiscard, who set up the Duchy of Apulia. Byzantium was ejected from Apulia in 1071 when the Normans took Bari. This date resonates ominously in Byzantine history, for in 1071 the Seljuks won their important victory at Mantzikert in Asia Minor.
BARI. Fortified city in Apulia on the Adriatic Sea, and the center of Byzantine operations in southern Italy from the time of its reconquest by Basil I in 876 to 1071 when the Normans conquered Bari. The date 1071 is among the most ominous in the history of Byzantium, for it was not only the year the Byzantines were ejected from Italy but also the year of the battle of Mantzikert, which marked the beginning of Seljuk expansion in Asia Minor.
BENEVENTO. City in central Italy that suffered in the wars between Justinian I and the Ostrogoths. Totila finally destroyed its walls in 545. The Lombards occupied it from ca. 570, creating the duchy of Benevento, which included Capua and Salerno until the ninth century. Benevento became independent in 774, when Charlemagne destroyed the Lombard state. Thereafter, it switched acknowledgement of technical suzerainty from Charlemagne’s successors to Byzantium (Leo VI reoccupied it briefly from 891–895, and again in 1042–1051), then to the Normans and to the papacy, as the situation demanded.
BRINDISI. Important commercial port in Apulia, and terminus of the Via Appia, the Roman road that went to Rome via Capua. Its chief strategic importance lay in the fact that it was a main point of embarkation for Dyrrachion, across the Adriatic Sea, where the Via Egnatia began. This fact explains the importance of Brindisi to the Normans, and why they conquered it in 1071, making it a staging area for attacks on Dyrrachion.
CALABRIA. From about the middle of the seventh century the term no longer designated all of southern Italy, but only the peninsula (Bruttium in antiquity) that forms the toe of the Italian “boot,” separated from Sicily by the Strait of Messina. After the Arab conquest of Sicily in 902, Calabria was reorganized into a theme, which continued to be threatened by Arabs and Lombards in the 10th and 11th centuries. Norman expansion in southern Italy resulted in the conquest of Calabria by 1059. Norman suppression of the Greek rite in Calabria and Apulia was closely intertwined with the schism between the churches in 1054.
(Source: «Historical Dictionary of Byzantium», by John H. Rosser)