Kingdom of Sicily, The Norman Rule

By the 11th century mainland southern Italian powers were hiring Norman mercenaries, who were descendants of the Vikings; it was the Normans under Roger I who conquered Sicily, taking it away from the Arab Muslims. After taking Apulia and Calabria, he occupied Messina with an army of 700 knights. In 1068, Roger I of Sicily and his men defeated the Muslims at Misilmeri but the most crucial battle was the siege of Palermo, which led to Sicily being completely under Norman control by 1091.

The Norman Kingdom was created on Christmas Day, 1130, by Roger II of Sicily, with the agreement of Pope Innocent II, who united the lands Roger had inherited from his father Roger I of Sicily. These areas included the Maltese Archipelago, which was conquered from the Arabs of the Emirates of Sicily; the Duchy of Apulia and the County of Sicily, which had belonged to his cousin William II, Duke of Apulia, until William's death in 1127; and the other Norman vassals. Roger threw his support behind the Antipope Anacletus II, who enthroned him King of Sicily on Christmas Day 1130.

In 1136, the rival of Anacletus, Pope Innocent II, convinced Lothair III, Holy Roman Emperor to attack the Kingdom of Sicily with help from the Byzantine Emperor John II Comnenus. Two main armies, one led by Lothair, the other by Duke of Bavaria Henry the Proud, invaded Sicily. On the river Tronto, William of Loritello surrendered to Lothair and opened the gates of Termoli to him. This was followed by Count Hugh II of Molise. The two armies were united at Bari, from where in 1137 they continued their campaign. Roger offered to give Apulia as a fief to the Empire, which Lothair refused after being pressured by Innocent. At the same period the army of Lothair revolted. Then Lothair, who had hoped for the complete conquest of Sicily, gave Capua and Apulia from the Kingdom of Sicily to Roger's enemies. Innocent protested, claiming that Apulia fell under papal claims. Lothair turned north, but died while crossing the Alps on December 4, 1137. At the Second Council of the Lateran in April 1139, Innocent excommunicated Roger for maintaining a schismatic attitude.

On March 22, 1139, at Galluccio, Roger's son Roger III, Duke of Apulia ambushed the papal troops with a thousand knights and captured the pope. On March 25, 1139, Innocent was forced to acknowledge the kingship and possessions of Roger with the Treaty of Mignano. Roger spent most of the decade, beginning with his coronation and ending with the Assizes of Ariano, enacting a series of laws with which Roger intended to centralise the government, fending off multiple invasions and quelling rebellions by his premier vassals: Grimoald of Bari, Robert II of Capua, Ranulf of Alife, Sergius VII of Naples and others. It was through his admiral George of Antioch that Roger then proceeded to conquer the Mahdia in Africa, taking the unofficial title "King of Africa".

At the same time Roger's fleet attacked the Byzantine Empire, making Sicily the leading maritime power in the Mediterranean Sea for almost a century. Roger's son and successor was William I of Sicily, known as "William the Bad", though his nickname derived primarily from his lack of popularity with the chroniclers, who supported the baronial revolts which William suppressed. His reign ended in peace (1166), but his son, William II, was a minor. Until the end of the boy's regency in 1172, the kingdom saw turmoil which almost brought the ruling family down.

The reign of William II is remembered as two decades of almost continual peace and prosperity. For this more than anything, he is nicknamed "the Good". He died in 1189 without having heirs, which led the kingdom to decline. Tancred of Lecce seized the throne but had to contend with the revolt of his distant cousin Roger of Andria and the invasion of Henry VI, Holy Roman Emperor on behalf of his wife, Constance, the daughter of Roger II. Constance and Henry eventually prevailed and the kingdom fell in 1194 to the House of Hohenstaufen. Through Constance, the Hauteville blood was passed to Frederick II, Holy Roman Emperor.