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.
Geology of Sicily well as the regional uplift of the Calabrian unit. The tectonic setting of Sicily is controlled by the rate of collision of the African plate and Eurasian plate and the rate of back rolling of the African plate. The tectonic history of Sicily can be divided into four main stages: During Late Triassic, the ancient Neotethys ocean was formed by a major continental rifting event and rapid tectonic subsidence. Traces of the tectonic event can be found at both the Hyblean plateau and western Sicily. After the rapid subsidence during Triassic to Early Jurassic, there was a slow thermal subsidence