The 5th Marine Division was a United States Marine Corps infantry division. Created during World War II, the 5th Division saw its first combat action during the Battle of Iwo Jima in 1945 where it sustained the highest number of casualties of the three Marine divisions of the V Amphibious Corps (invasion force). The 5th Division was to be part of the planned invasion of the Japan homeland before Japan surrendered. The 5th Division received the Presidential Unit Citation for extraordinary heroism on Iwo Jima in February 1945 (awarded to the V Amphibious Corps). The 5th Division was disbanded in 1946.