County of Sicily with Robert Guiscard. In fact, the seat of Roger I's government was the Calabrian town of Mileto. According to the historians Agostino Inveges and Matteo Camera Roger I started to use the title ""Great Count of Sicily and Calabria"" since 1096. After the death of Roger I the major change was the transfer of the capital: Palermo became the capital in 1112, when Roger II was invested with the County, after the regency of the mother Adelaide del Vasto. With this change, Sicily come to be governed by the central government, while the Calabrian territories became a provincial administrative unit.
History of Sicily mainland part (still known as the Kingdom of Sicily as well). The ensuing War of the Sicilian Vespers lasted until the peace of Caltabellotta in 1302, although it was to continue on and off for a period of 90 years. With two kings both claiming to be the King of Sicily, the separate island kingdom became known as the Kingdom of Trinacria. It is this very split that ultimately led to the creation of the Kingdom of the Two Sicilies some 500 years on. "See also: " Peter III's son, Frederick III of Sicily (also known as Frederick II of