As mercenaries they fought the enemies of the Italian city-states, sometimes fighting for the Byzantines and sometimes against them, but in the following century they gradually became the rulers of the major polities south of Rome.

[a][10] The story in Icelandic sources suggests that Sigurd called Roger the king of Sicily twenty years before the latter actually obtained this title.

In 1112, at the age of sixteen, Roger began his personal rule, being named "now knight, now count of Sicily and Calabria" in a charter document dated 12 June 1112.

In 1122, Duke William II of Apulia, who was fighting with Count Jordan of Ariano, offered to renounce his remaining claims to Sicily as well as part of Calabria.

In September 1129 Roger was generally recognized as duke of Apulia by Sergius VII of Naples, Robert of Capua, and the rest.

[15][16] This lavish item, made for special events to show power and regality, was most likely worn as a symbol of the Norman's victory and new dynasty in Sicily.

It is a luxury object made from red silk imported from the Byzantine Empire, its outer panels embellished with gold embroidery, pearls, enamel and jewels.

[23] The inscription written in the tiraz band along the bottom of the piece states, "Here is what was created in the princely treasury, filled with luck, eminence, majesty, perfection, long-suffering, superiority, welcome, prosperity, liberality, brilliance, pride, beauty, the fulfillment of desires and hopes, the pleasure of days and nights, without cease or change, of glory, devotion, preservation of protection, luck, salvation, victory and capability, in the capital of Sicily, in the year 528 H. [1133–1134]"[17][24] This mantle was made to promote status, bring the wearer good fortune, and to emphasize Roger II's regal power.

In addition to its lavish decoration and color, the mantle uses striking imagery to convey Roger II's power and victory over the previous dynasty.

In a scene evoking domination through primal violence, two lions, a heraldic symbol of a powerful, male ruler, each attack a camel, addorsed on either side of a central palm tree.

First Roger dealt with a rebellion in Apulia, where he defeated and deposed Grimoald, Prince of Bari, replacing him with his second son Tancred.

Ranulf joined Robert and Sergius there, encouraged by news coming from Sicily that Roger was fatally ill or even already dead.

The royal army, split into several forces, easily conquered Aversa and even Alife, the base of the natural rebel leader, Ranulf.

Most of the rebels took refuge in Naples, which was besieged in July, but despite poor health conditions within the city, Roger was unable to take it, and returned to Messina late in the year.

In 1136, the long-awaited imperial army, led by Lothair and the Duke of Bavaria, Henry the Proud, descended the peninsula to support the three rebels.

Roger remained in Sicily, leaving its mainland garrisons helpless under the chancellor Robert of Selby, while even the Byzantine emperor John II Comnenus sent subsidies to Lothair.

At San Severino, after the victorious campaign, he and the pope jointly invested Ranulf as Duke of Apulia in August 1137, and the emperor then retired to Germany.

From there Roger moved to Benevento and northern Apulia, where Duke Ranulf, although steadily losing his bases of power, had some German troops plus some 1,500 knights from the cities of Melfi, Trani, Troia, and Bari, who were "ready to die rather than lead a miserable life".

On 30 October 1137, at the Battle of Rignano (next to Monte Gargano), the younger Roger and his father, with Sergius of Naples, met the defensive army of Duke Ranulf.

While the Count of Alife hesitated, Roger, now supported by Benevento, destroyed all the rebels' castles in the region, capturing an immense booty.

[28] In the summer of 1139, Innocent II invaded the kingdom with a large army, but was ambushed on 22 July 1139 at Galluccio,[29] southeast of present-day Cassino, by Roger's son and was captured.

While his sons overcame pockets of resistance on the mainland, on 5 November 1139 Roger returned to Palermo to plan a great act of legislation: the Assizes of Ariano, an attempt to establish his dominions in southern Italy as a coherent state.

He returned to check on his sons' progress in 1140 and then went to Ariano, a town central to the peninsular possessions (and a center of rebellion under his predecessors).

Roger's reforms in laws and administration aimed not only to strengthen his rule but also to improve the economic standing of Sicily and southern Italy.

At Palermo, he gathered round him distinguished men from a variety of ethnicities and cultures, such as the famous Arab geographer Muhammad al-Idrisi[34] and the Byzantine Greek historian Nilus Doxopatrius [35] or Neilos Doxapatres.

Sicily, in the center of the Mediterranean and a natural stopping point for people traveling across it, had been run by several different groups in its history, and Roger welcomed the learned and practiced tolerance toward the several religions, ethnicities and languages of his realm.

These conquests were lost in the reign of Roger's successor William, however, and never formed an integral part of the kingdom in southern Italy.

It also afforded him an opportunity, through the agency of Theodwin, a cardinal ever-vigilant for Crusade supporters, to strike up a correspondence with Conrad III of Germany in an effort to break his alliance with Manuel I Comnenus.

According to Nicetas Choniates, the island capitulated thanks to George's bribes (and the tax burden of the imperial government), welcoming the Normans as their liberators.

Studiorum Universitas Ruggero II, a private non-traditional university connected to Accademia Normanna was incorporated in the U.S. on 30 April 2001 in his honor.