Corsica and killings culminated in the assassination of Prefect Claude Érignac in 1998. In 2013, Corsica hosted the first three stages of the 100th Tour de France, which passed through the island for the first time in the event's 110-year history. Corsica was formed about 250 million years ago with the uplift of a granite backbone on the western side. About 50 million years ago sedimentary rock was pressed against this granite, forming the schists of the eastern side. It is the most mountainous island in the Mediterranean, a "mountain in the sea". It is also the fourth largest island in
Medieval Corsica the island was placed under the government of the newly organized Praetorian prefecture of Africa. However, the exarchate was not able to protect the island from the raiding by the Ostrogoths and the Lombards, who moved down into Italy from the north beginning in 568. After the loss of the African mainland territories of the exarchate to the Umayyad dynasty in 709, the empire's power in the West deteriorated further. Saracen raiders began to prey on Corsica, leading Liutprand the Lombard to invade circa 725 to preempt Saracen designs. The first Muslim raid on Corsica took place in 713. These