Final answer:
At the Yalta Conference in 1945, Franklin Roosevelt of the USA, Winston Churchill of Great Britain, and Joseph Stalin of the Soviet Union met to discuss postwar restructuring.
Step-by-step explanation:
The Yalta Conference, a pivotal event during February 1945 in the Soviet Union, included the participation of three key leaders discussing the future of Europe following World War II.
The attendees of this critical meeting were Franklin Delano Roosevelt of the United States, Winston Churchill of Great Britain, and Joseph Stalin of the Soviet Union. At this conference, the division of Germany, the establishment of the United Nations, and the reconstruction of postwar Europe were significant topics.
While other figures such as Harry Truman and Clement Attlee played roles in the later Potsdam Conference, they were not participants in the Yalta discussions.
The decisions made at Yalta set the stage for the post-war geopolitical landscape and contributed to the onset of the Cold War by addressing issues like the unconditional surrender of Germany, the division of Eastern Europe, and the reparations and rebuilding following the immense destruction of the war.