Saint Martin , officially the Collectivity of Saint Martin (French: Collectivité de Saint-Martin) is an overseas collectivity of France located in the Caribbean. It came into being on 15 July 2007, encompassing the northern 60% of Saint Martin island and neighbouring islets, the largest of which is Île Tintamarre. The southern 40% of the island, Sint Maarten, is one of the four constituent countries that form the Kingdom of the Netherlands.