The ruined, supposedly Roman, fortification called
Lucilinburhuc was first mentioned in 963, when Count
Siegfried acquired it from Wikerus,
Abbot of
St. Maximin's Abbey in
Trier. Siegfried first appeared about 950. He was possibly a son of
Gilbert, Duke of Lorraine, and his mother
Cunigunda was a granddaughter of the
West Frankish King
Louis the Stammerer. In the following years, Siegfried built a new castle on the site of the ruins, on a rock later called "
Bockfiels". The castle dominated a stretch of the old
Roman road linking
Reims,
Arlon and
Trier that provided prospects for trade and taxation. Although the history of Luxembourg began with the castle's construction, it seems that Siegfried and his immediate successors did not make the castle their primary residence. During the following years, a small town and market grew around the new castle. Its first inhabitants were probably servants of Count Siegfried and clergy of Saint Michael's Church. The settlement soon received additional protection by the construction of a partial
city wall and
moat. In addition to the small town near the
Bockfiels and the Roman road, a further settlement was established in the Alzette Valley, today the
Grund quarter of Luxembourg. By 1060 the fortress had been extended by Siegfried's descendants.
Conrad I (d. 1086) was the first to call himself a "Count of Luxembourg". His son,
Henry III, was the first count known to have established his permanent residence there, as in a 1089 document, he is referred to as "comes Henricus de Lutzeleburg". By 1083, this lower town contained two churches and bridges over the
Alzette and
Petruss rivers. Its inhabitants' occupations included fishing, baking, and milling. In the same year, the
Benedictine abbey of
Altmünster was founded on the hill behind the castle by
Conrad I, Count of Luxembourg. In 1136 when Count
Conrad II of Luxembourg died without heirs, the Ardennes–Luxembourg branch became extinct and the county, by order of Emperor
Lothair II, passed to Conrad's maternal cousin
Henry the Blind from the
House of Namur. When Henry the Blind died in 1196,
Count Otto I of Burgundy (a son of the
Hohenstaufen emperor
Frederick Barbarossa) raised claims to the throne. Henry the Blind's daughter,
Ermesinde, married
Count Theobald I of Bar, thus securing her own succession as Countess of Luxembourg. The town of Luxembourg became the centre of a state of strategic value in the
Low Countries. Its fortifications were steadily enlarged and strengthened over the years by successive owners, which made it one of the strongest fortresses in Europe. Through its formidable defences it became known as the "Gibraltar of the North". The Luxembourg counts lost the Limburg heritage when they were defeated by the
Dukes of Brabant in the 1288
Battle of Worringen. Nevertheless, Count
Henry VII, whose father
Henry VI had been killed in battle, settled the quarrel by marrying
Margaret of Brabant in 1292. In 1308, he was elected
King of the Romans and was crowned
Holy Roman Emperor in 1312, the first of three emperors provided by the House of Luxembourg. His son,
John the Blind, became
King of Bohemia in 1310, whereafter the dynasty moved their seat of power to
Prague Castle. ==Elevation==