The Convention between Belgium and the Grand Duchy of Luxembourg for the establishment of an economic union was signed in Brussels on 25 July 1921, in two authentic copies, the official text being French. Plenipotentiaries: Henri Jaspar, Belgian Minister for Foreign Affairs, and Emile Reuter, Minister of State and Prime Minister of Luxembourg. Article 30: approval by the chambers, ratification and exchange in Brussels. The exchange: 6 March 1922. LNTS No. 256, volume 9, registered on 10 April 1922. It is not the 1944 Benelux arrangement, nor the 2002 convention.

Article 1: a customs union. Article 2: from entry into force, the territories form a single area for customs and common excise duties; the internal customs frontier is abolished. Article 3: commerce shall be entirely free, without prohibitions or charges, save the exceptions in the convention; national treatment for persons, trade and public tenders. Article 4: Luxembourg customs legislation is replaced by the Belgian; later modifications go to the Superior Council for its opinion. Article 5: future commercial treaties are concluded by Belgium on behalf of the union, after consulting Luxembourg.

Articles 6–8: alignment of non-common excise duties, and no export bounties between the parties. Article 11: customs and common excise receipts, after costs, are shared in proportion to population. Article 19: a Mixed Administrative Council in Brussels (two Belgians, including the chairman, and one Luxembourger). Article 21: after ratification the Grand-Ducal Government promulgates the required provisions; pooling of receipts from the first of the following month.

Article 27: the Superior Council of the Union, five members (three Belgian, two Luxembourg), an advisory body. Article 28: arbitration in Brussels, with a third arbitrator from a friendly third State, appointed if need be by the League of Nations Office — treaty procedure, not a litigation handbook. Article 29: a term of fifty years from ratification, then ten-year extensions unless denounced one year in advance.

Cover: Egmont Palace in Brussels, a seat of Belgian diplomacy; we do not claim the hall. Wikimedia Commons, free licence.

Sources consulted: Belgium–Luxembourg Economic Union; Convention for the establishment of an Economic Union (LNTS No. 256).