When, in 1890, Grand Duke William III died without any male heirs, the Grand Duchy passed out of Dutch hands, and into an independent line under Grand Duke Adolphe.Thus, Luxembourg, which had hitherto been independent in theory only, became a truly independent country, and Luxembourg City regained some of the importance that it had lost in 1867 by becoming the capital of a fully independent state.Nonetheless, the Austrian garrison eventually surrendered, and as a consequence, Luxembourg was annexed by the French Republic, becoming part of the département of Forêts, with Luxembourg City as its préfecture.
Under the occupation, the capital city's streets all received new, German names, which was announced on 4 October 1940.
The city was under long-range bombardment by the German V-3 cannon in December 1944 and January 1945.
Siegfried built his castle, named Lucilinburhuc ("small castle"), on the Bock Fiels ("rock"), mentioned for the first time in the aforementioned exchange treaty.
In 987, Archbishop Egbert of Trier consecrated five altars in the Church of the Redemption (today St. At a Roman road intersection near the church, a marketplace appeared around which the city developed.
In the 17th century, the first casemates were built; initially, Spain built 23 km (14 mi) of tunnels, starting in 1644.
These were then enlarged under French rule by Marshal Vauban, and augmented again under Austrian rule in the 1730s and 1740s.In the Roman era, a fortified tower guarded the crossing of two Roman roads that met at the site of Luxembourg city.Through an exchange treaty with the abbey of Saint Maximin in Trier in 963, Siegfried I of the Ardennes, a close relative of King Louis II of France and Emperor Otto the Great, acquired the feudal lands of Luxembourg.Luxembourg became part of the Burgundian, and later Spanish and Austrian empires (See Spanish Netherlands and Spanish road) and under those Habsburg administrations Luxembourg Castle was repeatedly strengthened so that by the 16th century, Luxembourg itself was one of the strongest fortifications in Europe.Subsequently, the Burgundians, the Spanish, the French, the Spanish again, the Austrians, the French again, and the Prussians conquered Luxembourg.In 1967, the High Authority was merged with the commissions of the other European institutions; although Luxembourg City was no longer the seat of the ECSC, it hosted some part-sessions of the European Parliament until 1981.