In 963 Sigefroi (or Siegfried, count of the Ardennes) built a castle on a rocky spur, so laying the foundations of the present-day capital. Sigefroi ruled the area as a fiefdom while his successors became vassals of the Holy Roman emperor. In 1354 the region became an independent duchy and its ruler, Wenceslas I, son of John the Blind, vastly extended the duchy’s lands, incorporating Metz in the south and Limburg to the north. But the fort’s strategic position made it much sought-after and the city’s history, from here until 1815, runs largely parallel to Belgium’s.
After Napoleon’s defeat at Waterloo in 1815, the Congress of Vienna decided Luxembourg should become an independent Grand Duchy. It was ceded to King William I of Orange-Nassau, the ruler of the United Kingdom of the Netherlands, as his personal property; he was installed as the first grand duke. The Grand Duchy remained the property of the Dutch monarchy until 1890 when, due to the lack of a male heir, the crown passed to Duke Adolph of Nassau who headed a branch of the Nassau family and whose descendants rule to this day. For details on Luxembourg’s current ducal family, see boxed text.
In 1839, under the Treaty of London, the Grand Duchy was split in two. Belgium received the western portion, while William I kept the eastern side. The present-day borders were set. Recognising Luxembourg’s potentially perilous position between France and Germany, Luxembourg was declared neutral in 1867. As a result, much of its historic fortifications were dismantled.