At the Luxembourg Castle, in the Luxembourg City, the capital of Luxembourg

 The City of Luxembourg has a little bit of everything, and for such a small country, it is packed with a history spanning more than a thousand years.

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Luxembourg, also known as Luxembourg City, is the capital of Luxembourg and the country's most populous commune. The city lies at the heart of Western Europe It contains Luxembourg Castle, established by the Franks in the Early Middle Ages.

+ Luxembourg is now ranked by the IMF as having the highest GDP per capita in the world. It is one of the de facto capitals of the European Union (alongside Brussels, Frankfurt, and Strasbourg), as it is the seat of several institutions, agencies, and bodies, including the Court of Justice of the European Union, the European Court of Auditors, the Secretariat of the European Parliament, the European Public Prosecutor's Office, the European Investment Bank, the European Investment Fund, and the European Stability Mechanism, Eurostat. The Council of the European Union meets in the city for three months annually.

+ The city has long been a place of strategic military significance. The first fortifications were built as early as the 10th century. By the end of the 12th century, as the city expanded westward around the new St. Nicholas Church (today the Cathedral of Notre Dame), new walls were built that included an area of 5 hectares (12 acres). the Burgundians under Philip the Good conquered Luxembourg. which became part of the Burgundian, and later Spanish and Austrian empires 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.

+ During the French Revolutionary Wars, the city was occupied by France twice: once, briefly, in 1792–93, and, after a seven-month siege, Luxembourg held out for so long under the French siege that French politician and military engineer Lazare Carnot called Luxembourg "the best fortress in the world, except Gibraltar", giving rise to the city's nickname: the "Gibraltar of the North."

+ After the Luxembourg Crisis, the 1867 Treaty of London required Luxembourg to dismantle the fortifications in Luxembourg City. Despite Luxembourg's efforts to remain neutral in WWI, it was occupied by Germany on 2 August 1914. Luxembourg City was the scene of an attempted communist revolution; on 9 November 1918. In 1940, Germany occupied Luxembourg again; the city was liberated on 10 September 1944. After the war, Luxembourg remains the seat of the European Parliament's secretariat, as well as the Court of Justice of the European Union, the European Court of Auditors, and the European Investment Bank. Several departments of the European Commission are also based in Luxembourg. (The Council of the EU meets in the city for the months of April, June and October annually.)