Between the two wars, Paris was the capital of modern art and a magnet for intellectuals, writers and artists from around the world. The population reached its historic high of 2.1 million in 1921, but declined for the rest of the century. New museums (The Centre Pompidou, Musée Marmottan Monet and Museé d'Orsay) were opened, and the Louvre given its glass pyramid.