Sicilian-Byzantine Wars
The Sicilian-Byzantine Wars were a series of conflicts in the mid-12th century between the Byzantine Empire and the Kingdom of Sicily, ruled by Roger II and later his successors. These wars emerged from territorial disputes and power struggles in the eastern Mediterranean, following the failure of earlier Norman attempts to conquer Byzantium. Roger II sought to expand his influence through military action after a proposed marriage alliance with Byzantine Emperor Manuel I fell through. During the Second Crusade, Roger capitalized on the weakened state of the Byzantine Empire, launching attacks on key cities such as Corfu and Athens, and relocating valuable resources back to Sicily.
The conflict saw shifting alliances, with the Byzantines attempting to regroup through collaborations with Venice and other powers, including the Pope. After Roger's death in 1154, his successor William I faced renewed Byzantine aggression but managed to reclaim lost territories through a series of strategic military campaigns. By the late 12th century, the Sicilian forces, under King William II, mounted a significant offensive that briefly captured parts of the Byzantine Empire, including Thessalonica. However, internal strife within the Byzantine leadership ultimately led to a unified response that expelled the Sicilian forces from the mainland by 1185. By 1191, the Kingdom of Sicily had diminished its territorial claims to only a small part of the Byzantine realm, reflecting the broader regional shifts of power during this tumultuous period.
On this Page
Sicilian-Byzantine Wars
At issue: The Sicilian kings’ desire to rule the Byzantine Empire; the Byzantine emperor’s desire to reconquer southern Italy
Date: Autumn, 1147-January, 1158; June, 1185-spring, 1186
Location: Albania, Greece, southern Italy
Combatants: Italian Normans and their allies vs. the Byzantine Empire and its allies
Principal commanders:Sicilian, King Roger II (1095–1154), King William I (1120–1166), Count Tancred of Lecce (1135–1194); Byzantine, Emperor Manuel I (1118–1180), Emperor Andronicus I Comnenus (c.1120–1185), Alexios Branas (1166–1187)
Principal battles: Siege of Corfu, Andria, Siege of Brindisi, Thessalonica, Mosynopolis
Result: Byzantines failed to reconquer southern Italy; Sicilians failed to retain any imperial territory
Background
In the mid-twelfth century, the Byzantine Empire and Roger II’s kingdom of Sicily (southern Italy and Sicily) were the major rivals for power in the eastern Mediterranean. Though his ancestors had failed to seize Byzantium during the Norman-Byzantine Wars (1081–1108), Roger had much greater power. When Emperor Manuel I rebuffed a proposed marriage alliance, Roger prepared an invasion. Manuel, for his part, wanted to follow his father John’s plan for an alliance with Germany against the Sicilian kingdom, with an eye on reconquering these Byzantine territories lost a century before. Meanwhile, Conrad III of Germany and Louis VII of France were assembling the Second Crusade. In the summer of 1147, the crusaders marched in two waves through the empire and Constantinople, causing the disruption Roger needed. As Conrad’s army was being destroyed by the Turks near Dorylaeum, Roger struck.
Action
The Sicilian fleet attacked Corfu, Euboea, and Athens, and sacked the wealthy cities of Thebes and Corinth, relocating many valuable silk workers to Palermo. Manuel quickly allied himself with Venice and Conrad, who sought hospitality after his bitter defeat. Roger, a master strategist, funded a revolt by Duke Welf in Germany that tied Conrad down and an invasion of the Balkans by Serbs and Hungarians. He also gained the support of Pope Eugenius III and Louis VII, who blamed Manuel for the failure of the Second Crusade. The Byzantine and Venetian fleets retook Corfu in 1148; Conrad and Manuel planned an attack on southern Italy for 1149. Roger’s diplomacy and Conrad’s death in February, 1152, delayed the offensive. Conrad’s successor, Frederick I Barbarossa, had his own imperial ambitions and eventually supported the Sicilians.
Roger died in 1154, and his successor William I tried to placate Manuel, who took these overtures as signs of weakness. Rebellious Norman nobles gave Manuel the support he needed in Italy; he landed an army at Ancona in late summer, 1155. William’s viceroy, Asclettin, and his 2,000 knights suffered defeat in September near Andria, and Pope Hadrian IV sent a mercenary army against William to establish papal claims. By year’s end, most of Campania and Apulia were in papal or Byzantine hands. The following spring, William launched a brilliant counterattack by land and sea that split the allies and frightened off the mercenaries and rebels. He broke the Byzantine Siege of Brindisi on May 28, 1156, and soon regained all his lost territory.
In summer, 1157, with more than 164 ships and 10,000 men, William attacked Euboea, Almira, and Constantinople itself, while Manuel started a successful revolt back in Italy. This gave the Byzantines leverage in treaty negotiations brokered by Pope Hadrian IV.
In spring, 1185, Sicilian king William II assembled the largest Sicilian force to date: more than 200 ships and 80,000 fighting men. Count Tancred of Lecce led the assault on Dyrrachium, which fell June 24. Following the Via Egnatia toward Constantinople, the Sicilians were outside of Thessalonica, Byzantium’s second city, by August 6. On August 24, they broke in and pillaged and slaughtered. The tyrannical and hated Emperor Andronicus I Comnenus sent a divided force against the Sicilians, but these detachments avoided battle, and Andronicus was violently overthrown and replaced by Isaac Angelos. Isaac unified and reinforced this army under Alexios Branas, who defeated the Sicilians at Mosynopolis (1185) and eventually drove them off of the Byzantine mainland.
Aftermath
By 1191, the Sicilians held only the island of Cephalonia in the Byzantine Empire.
Bibliography
Douglas, David. The Norman Fate, 1100–1154. Berkeley: University of California Press, 1976.
Magdalino, Paul. The Empire of Manuel I Komnenos, 1143–1180. New York: Cambridge University Press, 1993.
Magoulias, Harry, trans. O City of Byzantium: Annals of Niketas Choniates. Detroit, Mich.: Wayne State University Press, 1984.
Matthew, Donald. The Norman Kingdom of Sicily. New York: Cambridge University Press, 1992.