These extremely rare and museum-grade World War II artifacts are original “CONFIDENTIAL” marked Operation Downfall FIRST PROOF planning maps used by the Combined Chiefs of Staff (CCS) during the top secret planning of mainland Japan. The Combined Chiefs of Staff (CCS) was the supreme military staff for the United States and Britain during World War II. It set all the major policy decisions for the two nations, subject to the approvals of British Prime Minister Winston Churchill and U.S. President Franklin D. Roosevelt. Operation Olympic was a planned Allied (American and British) invasion during World War II, intended as the first major phase of Operation Downfall, which was the overall Allied plan for the invasion of the Japanese home islands. Set to begin in November 1945, Operation Olympic aimed to capture the southern Japanese island of Kyushu as a staging area for the subsequent invasion of the main island, Honshu, under Operation Coronet. The preparation for Olympic involved intricate planning, massive troop mobilizations, and considerable logistical challenges. It was expected to be the largest amphibious operation in the history of warfare, overshadowing even the D-Day landings in Normandy. This Operation Downfall double-sided Combined Chiefs of Staff (CCS) intelligence planning map is one of only a handful that still exist as these intelligence maps were closely guarded due to the invasion information they contained.