Most French rulers since the Middle Ages made a point of leaving their mark on a city that, contrary to many other of the world's capitals, has never been destroyed by catastrophe or war. In modernising its infrastructure through the centuries, Paris has preserved even its earliest history in its street map. At its origin, before the Middle Ages, the city was composed of several islands and sandbanks in a bend of the Seine; of those, two remain today: Île Saint-Louis and the Île de la Cité. A third one is the 1827 artificially created Île aux Cygnes.