Geneva 1 July 2003. Fifty years ago today, representatives of the twelve founding Member States of CERN1 signed the Organization's convention, paving the way for the establishment of the world's leading fundamental physics research institution. Today, CERN numbers 20 European Member States, with several countries from beyond the European region also participating in the Laboratory's world-class research programme. CERN officially came into existence on 29 September 1954, when the founding Member States ratified the convention.