Final answer:
The Big Three (Churchill, Stalin, and Roosevelt) met at the Yalta Conference in 1945 to discuss wartime strategy, the United Nations, and the reconstruction of Europe.
Step-by-step explanation:
The Big Three (British Prime Minister Winston Churchill, Soviet Premier Josef Stalin, and US President Franklin Roosevelt) met at the Yalta Conference in February 1945 to discuss several important issues.
These included wartime strategy, the creation of the United Nations, and the reconstruction of Europe. The leaders also discussed their joint occupation of Germany and plans for postwar Europe, as well as the defense of the Soviet Union through the establishment of a Russian sphere of influence in Poland and Eastern Europe.