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
Roman Catholic Diocese of Mariana in Corsica Roman Catholic Diocese of Mariana in Corsica The Diocese of Mariana in Corsica () was a Roman Catholic ecclesiastical territory in Mariana, Corsica, in the north-eastern corner of the island. In 1563 the diocese was united with the Diocese of Acci(a) to form the Diocese of Accia and Mariana. Both dioceses were poor and had lost population. Mariana had been abandoned and its bishop lived in Bastia to the north, the seat of the civil government of the island. The Cathedral sat alone near the banks of the River Golo some three miles from the sea, in the midst of