Luxembourg an independent state under the personal possession of William I of the Netherlands with a Prussian garrison to guard the city against another invasion from France. In 1839, following the turmoil of the Belgian Revolution, the purely Oil-speaking part of Luxembourg was ceded to Belgium and the Luxembourgish-speaking part (except the Arelerland, the area around Arlon) became what is the present state of Luxembourg. Luxembourg is a founding member of the European Union, OECD, United Nations, NATO, and Benelux. The city of Luxembourg, which is the country's capital and largest city, is the seat of several institutions and agencies of
Battle of Belgium (German: "Zusammenfassender Bericht des Oberkommandos der Wehrmacht über die Operationen im Westen vom 10. Mai bis 4. Juni") reports: Battle of Belgium The Battle of Belgium or Belgian Campaign, often referred to within Belgium as the 18 Days' Campaign (, ), formed part of the greater Battle of France, an offensive campaign by Germany during the Second World War. It took place over 18 days in May 1940 and ended with the German occupation of Belgium following the surrender of the Belgian Army. On 10 May 1940, Germany invaded Luxembourg, the Netherlands, and Belgium under the operational plan "Fall Gelb"