premise: Corsica is an book.
hypothesis: Corsica ( [ ˈkɔrsɪkə ] Corse [ kɔʁs ] Corsican and Italian : Corsica [ ˈkɔrsika ] ) is an island in the Mediterranean Sea and one of the 13 regions of France . A single chain of mountains makes up two-thirds of the island . The island formed a single department until it was split in 1975 into two departments : Haute-Corse ( Upper Corsica ) and Corse-du-Sud ( Southern Corsica ) , with its regional capital in Ajaccio , the prefecture city of Corse-du-Sud . After being ruled by the Republic of Genoa since 1284 , Corsica was briefly an independent Corsican Republic from 1755 until it was conquered by France in 1769 . This Mediterranean island was ruled by various nations over the course of history but had several brief periods of independence .