With the capture of Okinawa and the Philippines in 1945, the Allies had captured important territory in the western Pacific from which to base air, sea and land assets with which to engage in an invasion of the Japanese main islands. They called the entire project "Operation Downfall" and the first part of this colossal undertaking was called "Operation Olympic." The goal of Olympic was to capture airfields and ports in the southern half of the island of Kyushu from which they could use for the next phase of Downfall which was called "Operation Coronet," the invasion of the island of Honshu.
