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
Defensive Organization of Corsica and to support artillery batteries capable of controlling the Strait of Bonifacio between Corsica and the Italian island of Sardinia, separated by only twelve kilometers. As World War II unfolded, no attempt was made by Italian forces to mount an opposed landing on Corsica. The island was instead occupied in November 1942. In 1943 Corsica saw fighting when German forces moved from Sardinia. Most of the fortified positions remain to the present day. During the inter-war period, Corsica's defenses were first examined in 1926, when General Debeney requested a study of the island's defenses from Vice-Admiral Salaun, the French Navy