Thus, on 25 March 1957, the Treaties of Rome were signed. They came into force on 1958-01-01 establishing the European Economic Community (EEC) and the European Atomic Energy Community (Euratom). The latter body fostered co-operation in the nuclear field, at the time a very popular area, and the EEC was to create a full customs union between members. Louis Armand became the first President of Euratom Commission and Walter Hallstein became the first President of the EEC Commission.