Saint Martin is an island in the northeast Caribbean Sea, approximately 300 km east of Puerto Rico. The 87-square-kilometre island is divided roughly 60/40 between the French Republic (53 km2 and the Kingdom of the Netherlands (34 km2 but the two parts are roughly equal in population. The division dates to 1648. The southern Dutch part comprises Sint Maarten and is one of four constituent countries that form the Kingdom of the Netherlands. The northern French part comprises the Collectivity of Saint Martin and is an overseas collectivity of France. On 1 January 2009, the population of the whole island was 77,741 inhabitants, with 40,917 living on the Dutch side and 36,824 on the French side.