The political galaxy, in the same way as the increasing role played by artillery, was of great significance to the future of the city whose fate was a plaything of the major powers during the course of the 1540s. In the strife which took place between Francis I and Charles V, the city changed hands four times before finally resting in those of the Habsburgs. The latter decided to review the entire defensive system. After long and seemingly interminable works, which were drawn out over almost a century and a half, the fortified city had been transformed into a complete fortress.
At the end of a memorable siege, led by Vauban, the forces of the French King Louis XIV conquered Luxembourg in 1684. Vauban entirely redesigned the defences of the city, and made it into a formidable entity - formidable in the first meaning of the word, that is to say inspiring great fear and apprehension. Luxembourg returned to the Habsburgs in 1697, the city took on the nickname of "Gibraltar of the North" during the 18th.Century.
After a long blockade, the city of Luxembourg was conquered, in 1795, by the French Revolutionary troops. In 1815, after the creation of the Grand Duchy of Luxembourg, which became a member of the German Confederation, the city was made a federal fortress with a Prussian garrison.
During the 19th Century the conflict between the Bourbons and the Habsburgs had Luxembourg at the very front line between France and Germany. In fact a war over it almost broke out between Napoleon III and Bismarck in 1867. It was only possible to avoid it at the last moment. Thanks to the Treaty of London: the Grand Duchy was declared a neutral state, and the fortifications of the Capital were ordered to be dismantled. Nine centuries after Siegfried, Luxembourg had ceased to be a fortress. There are still remains of the impressive remparts, but they face another problem today - modern traffic.