The Battle of Dyrrhachium took place on October 18, 1081 between the Byzantine Empire, led by the Emperor Alexios I Komnenos (r. 1081–1118), and the Normans of southern Italy under Robert Guiscard, Duke of Apulia and Calabria. The battle was fought outside the city of Dyrrhachium (present-day Durrës in Albania), the major Byzantine stronghold in the western Balkans, and ended in a Norman victory. Following the Norman conquest of Byzantine Italy and Saracen Sicily, the Byzantine emperor, Michael VII Doukas (r. 1071–1078), betrothed his son to Robert Guiscard's daughter. When Michael was deposed, Robert took this as an excuse to invade the Byzantine Empire in 1081. His army laid siege to Dyrrhachium, but his fleet was defeated by the Venetians. On October 18, the Normans engaged a Byzantine army under Alexios I Komnenos outside Dyrrhachium. The battle began with the Byzantine right wing routing the Norman left wing, which broke and fled. Varangian mercenaries joined in the pursuit of the fleeing Normans, but became separated from the main force and were massacred. Norman knights in the centre attacked the Byzantine centre and routed it, causing the bulk of the Byzantine army to rout. After this victory, the Normans took Dyrrhachium in February 1082 and advanced inland, capturing most of Macedonia and Thessaly. Robert was then forced to leave Greece to deal with an attack on his ally, the Pope, by the Holy Roman Emperor, Henry IV (r. 1084–1105). Robert left his son Bohemond in charge of the army in Greece. Bohemond was initially successful, defeating Alexios in several battles, but was defeated by Alexios outside Larissa in 1083. Forced to retreat to Italy, Bohemond lost all the territory gained by the Normans in the campaign. The Byzantine recovery began the Komnenian restoration. Background The Normans first arrived in Southern Italy in 1015 from northern France and served local Lombard lords as mercenaries against the Byzantine Empire. As they were paid with lands, soon they were powerful enough to challenge Papal authority; in 1054, they defeated the Pope at the Battle of Civitate, forcing him to acknowledge their authority. In 1059, the Pope made Robert Guiscard, of the Hauteville family, Duke of Apulia, Calabria, and Sicily. However, most of Apulia and Calabria were in Byzantine hands, and Sicily was in Saracen hands. By 1071, Robert, together with his brother Roger, had taken over the last Byzantine stronghold in Italy, Bari. By