<P> Although the senior statesmen stopped working personally on the conference in June 1919, the formal peace process did not really end until July 1923, when the Treaty of Lausanne was signed ". </P> <P> The Conference opened on 18 January 1919 . This date was symbolic, as it was the anniversary of the proclamation of William I as German Emperor in 1871, in the Hall of Mirrors at the Palace of Versailles, shortly before the end of the Siege of Paris - a day itself imbued with significance in its turn in Germany as the anniversary of the establishment of the Kingdom of Prussia in 1701 . The Delegates from 27 nations (delegates representing 5 nationalities were for the most part ignored) were assigned to 52 commissions, which held 1,646 sessions to prepare reports, with the help of many experts, on topics ranging from prisoners of war, to undersea cables, to international aviation, to responsibility for the war . Key recommendations were folded into the Treaty of Versailles with Germany, which had 15 chapters and 440 clauses, as well as treaties for the other defeated nations . </P> <P> The five major powers (France, Britain, Italy, the U.S., and Japan) controlled the Conference . Amongst the "Big Five", in practice Japan only sent a former prime minister and played a small role; and the "Big Four" leaders dominated the conference . The four met together informally 145 times and made all the major decisions, which in turn were ratified by other attendees . The open meetings of all the delegations approved the decisions made by the Big Four . The conference came to an end on 21 January 1920 with the inaugural General Assembly of the League of Nations . </P> <P> Five major peace treaties were prepared at the Paris Peace Conference (with, in parentheses, the affected countries): </P>

Who was left out of the peace conference