Due to its strategic position in Europe, Luxembourg has been a formidable fortress until 1867, when its walls were dismantled. Its origin dates back to the year 963, when Count Siegfried built his fortress. During the centuries the fortifications were repeatedly expanded. In 1443 it was part of the House of Burgundy, in 1506 it came under Spanish rule, in 1684 under French and in 1714 under Austrian rule. In the Congress of Vienna of 1815 the Grand Duchy of Luxembourg was created. It was part of the German Confederation until 1867, when the Treaty of London granted its political neutrality.