Zurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in north-central Switzerland at the northwestern tip of Lake Zurich. The municipality has approximately 400,028 inhabitants, the urban agglomeration 1.315 million, and the Zurich metropolitan area 1.83 million. Zurich is a hub for railways, roads, and air traffic. Both Zurich Airport and railway station are the largest and busiest in the country. Permanently settled for around 2000 years, Zurich has a history that goes back to its founding by the Romans, who, in 15 BC, called it Turicum. However, early settlements have been found dating back more than 6400 years ago. During the Middle Ages, Zurich gained the independent and privileged status of imperial immediacy and, in 1519, became a primary centre of the Protestant Reformation in Europe under the leadership of Ulrich Zwingli.