Editing Robert Guiscard (section)

===Against the Byzantines===
In his last campaign, Guiscard attacked the [[Byzantine Empire]] itself, supporting the cause of [[Raiktor]], a monk who claimed to be deposed emperor [[Michael VII Doukas|Michael VII]]. Even after it was clear that Raiktor was lying, Robert didn't stop, believing that he himself had the right to rule the Byzantine Empire since [[Constantine Doukas (co-emperor)|Constantine Doukas]], son of the real Michael VII, had once been proposed to his daughter [[Olympias (daughter of Robert Guiscard)|Olympias]].<ref>The Alexiad, Book 1, Chapter 12</ref>

In May 1081 Robert sailed with an army of Norman and Lombard troop (1,300 knights according to [[Geoffrey Malaterra]], up to 10,000 troops according to [[Orderic Vitalis]]). In October 1081 defeated [[Alexios I Komnenos]] in the [[Battle of Dyrrhachium (1081)|Battle of Dyrrachium]], and by 1082 he had occupied [[Corfu]] and [[Durrës|Durazzo]]. In 1083, however, he was forced to return to Italy to help Pope Gregory VII, who was being besieged in [[Castel Sant'Angelo]] by Henry IV. In May 1084 Guiscard entered Rome, and forced Henry to retreat. A revolt of the citizens led to [[Sack of Rome (1084)|a three-day sack of the city]], after which Robert escorted the Pope out of the city. Guiscard's son [[Bohemond I of Antioch|Bohemond]], who had remained in the Balkans, had by this time lost his father's conquests. Robert returned to the Balkans and reoccupied Corfu and [[Cephalonia]], with the help of [[Dubrovnik|Ragusa]] and other dalmatian cities under the rule of king [[Demetrius Zvonimir]].<ref>Loud, pp. 214-217.</ref>{{sfn|Forbes|1879|page=413}}<ref>Ferdo Šišić, Povijest Hrvata u vrijeme narodnih vladara, 1925, Zagreb {{ISBN|86-401-0080-2}}</ref>