Leo III the Isaurian
In 718 the Emperor Leo III the Isaurian (718–741) suppressed a revolt in Sicily, and then detached southern Italy and Sicily from the metropolitan jurisdiction of the pope in Rome. In the ninth century, the patriarch of Constantinople raised the See of Palermo to the rank of metropolitan of all of Sicily. A protest against these actions was entered by Pope Nicholas I (858–867), in a letter of 25 September 860 to the Emperor Michael III.