The East Prussian Offensive was a strategic offensive by the Soviet Red Army against the German Wehrmacht on the Eastern Front (World War II). It lasted from 13 January to 25 April 1945, though some German units did not surrender until 9 May. The Battle of Königsberg was a major part of the offensive, which ended in victory for the Red Army.
After months of planning, the UN Conference on International Organization opened in San Francisco, 25 April 1945, attended by 50 governments and a number of non-governmental organizations involved in drafting the UN Charter.