In September 1956, due to a common foe during the Suez Crisis, an Anglo-French Task Force was created. French Prime Minister Guy Mollet proposed a union between the United Kingdom and the French Union with Elizabeth II as head of state and a common citizenship. As an alternative, Mollet proposed that France join the Commonwealth. The UK Prime Minister Anthony Eden rejected both proposals and France went on to join the Treaty of Rome, which established the European Economic Community and strengthened the Franco-German cooperation.