In February 1948, the Polish federalist Joseph Retinger, in 1946 co-founder, with the former Belgian Prime Minister Paul Van Zeeland, of the Independent League for Economic Cooperation (ILEC) and Secretary-General of the International Committee of the Movements for European Unity, invites all ardent supporters of the European cause to attend the Hague Congress (7–10 May 1948), of which the primary aim is to launch the European Movement.