may 15. 1955, 10 years after after the end of the second world war Vyacheslav Molotov (Soviet Union), John Foster Dulles (USA), Harold Macmillan (United Kingdom) and Antoine Pinay (France) on behalf of the Allies, and Leopold Figl as the Austrian foreign minister, as well as the four High Commissioners of the occupying powers: Ivan I. Ilitchov (Soviet Union), Geoffrey Arnold Wallinger (United Kingdom), Llewellyn E. Thompson Jr. (USA), Roger Lalouette (France) signed the "Staatsvertrag" (Austrian State Treaty) in the Schloss Belvedere (castle Belvedere) in Vienna.
more info: http://en.wikipedia.org/wiki/Austrian_State_Treaty