On 25 March 1957, in Rome, Paul-Henri Spaak (left), Belgian Foreign Minister and President of the Intergovernmental Conference on the Common Market and Euratom, and Baron Jean Charles Snoy et d'Oppuers (right), Secretary-General of the Belgian Ministry of Economic Affairs, sign the Treaties establishing the European Economic Community (EEC) and the European Atomic Energy Community (EAEC or Euratom). Among the members of the Belgian Delegation can be seen (from left to right) Roger de Staercke, Albert Hupperts, Robert Rotschild, Joseph Van Der Meulen and Pierre Staner.
The members of the Council of the Organisation for European Economic Cooperation (OEEC) on 17 February 1949. From left to right (front row): Max Petitpierre (Switzerland), Dr Östen Undén (Sweden), Joseph Bech (Luxembourg), Robert Schuman (France), Paul-Henri Spaak (Belgium), Sir Stafford Cripps (United Kingdom) and Count Carlo Sforza (Italy).
On 23 July 1955, on the margins of the work of the Spaak Committee on the European revival, the French Ambassador to the Netherlands, Jean-Paul Garnier, sends a telegram to French Foreign Minister Christian Pineau in which he outlines the views exchanged during a dinner at the Belgian Embassy. He describes the optimism and satisfaction of the Belgian Foreign Minister Paul-Henri Spaak and his Dutch counterpart Johan Willem Beyen, who are very pleased with the atmosphere and mood in which the work of the various delegations is being conducted.
The first sitting of the Consultative Assembly of the Council of Europe takes place on 10 August 1949. Among those taking part are Paul-Henri Spaak, Carlo Sforza, Edouard Herriot, Ernest Bevin and Robert Schuman.
On 10 September 1952, in Strasbourg, the Belgian, Paul-Henri Spaak, chairs the first session of the Common Assembly of the European Coal and Steel Community (ECSC).
On 22 January 1972, Walter Hallstein, Joseph Bech, Paul-Henri Spaak, Jean Monnet, Jean-Charles Snoy et d'Oppuers and Jean Duvieusart, in particular, attend the ceremony to mark the signature of the Treaties of Accession of Denmark, Ireland, Norway and the United Kingdom to the European Communities.
On 1, 2 and 3 June 1955, the Foreign Ministers of the six Member States of the European Coal and Steel Community (ECSC) meet in Messina to discuss the terms for a revival of the European integration process. From left to right: Johan Willem Beyen (Netherlands), Gaetano Martino (Italy), Joseph Bech (Luxembourg), Antoine Pinay (France), Walter Hallstein (FRG) and Paul-Henri Spaak (Belgium).
On 9 March 1950, in the daily French newspaper Le Monde, Paul-Henri Spaak, former Prime Minister of Belgium and President of the Consultative Assembly of the Council of Europe, gives his opinion on the question of the monarchy that is dividing Belgium.
On 16 April 1948, at the Château de la Muette in Paris, Paul-Henri Spaak, Belgian Prime Minister and Foreign Minister, signs the Convention establishing the Organisation for European Economic Cooperation (OEEC).