Korsika, the Greek Island, Is a Part of France.

The island of Korsika is very close to Italy and yet it's part of France. It was controlled by the Republic of Genoa for about 400-500 years, until the 18th century. According to this treaty, Korsika was ceded to France in 1768. The question naturally arises as to why is Korsika a part of France, even though it's geographically much closer to Italy.