County of Sicily was created by Robert Guiscard in 1071 for his younger brother Roger Bosso. Guiscard himself had received the title Duke of Sicily ("dux Siciliae") in 1059 from Pope Nicholas II as encouragement to conquer it from the Muslims. In 1061 the first permanent Norman conquest (Messina) was made and in 1071, after the fall of Palermo, the capital of the emirate and future capital of the county, Guiscard invested Roger with the title of count and gave him full jurisdiction in the island save for half the city of Palermo, Messina, and the Val Demone, which he retained for himself.
Sicily in 552. In 535, Emperor Justinian I made Sicily a Byzantine province and, as in Roman times, Greek continued to be the predominate language spoken on the island. After the advent of Islam, Sicily was invaded by the Arab forces of Caliph Uthman in 652, but the Arabs failed to make any permanent gains and returned to Syria after gathering some booty. Raids seeking loot continued until the mid-8th century. Byzantine Emperor Constans II decided to move from the capital Constantinople to Syracuse in Sicily during 660. The following year, he launched an assault from Sicily against the Lombard Duchy