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
Belgium of the European Union and the extraordinary and committee sessions of the European Parliament. Belgium shares borders with France (), Germany (), Luxembourg () and the Netherlands (). Its total surface, including water area, is 30,528 square kilometres from which land area alone 30,278 km. It lies between latitudes 49°30 and 51°30 N, and longitudes 2°33 and 6°24 E. Belgium has three main geographical regions; the coastal plain in the northwest and the central plateau both belong to the Anglo-Belgian Basin, and the Ardennes uplands in the southeast to the Hercynian orogenic belt. The Paris Basin reaches a small fourth