The American invasion of the island of Okinawa, codenamed Operation Iceberg, took place 1 April 1945. The Japanese military was determined to inflict a casualty rate so high that the U.S. government would choose not to invade the Japanese home islands. To this end, the southern portion of the island had been covered with the most extensive system of fortifications and fields of fire yet encountered in the Pacific War.
The island was not declared secure until 22 June, a period of 82 days. Lieutenant General Simon Bolivar Buckner Jr. became the highest ranking U.S. military officer to be killed in action in the Second World War.
US Tenth Army
Lieutenant General Simon Bolivar Buckner Jr., USA (KIA 18 Jun)
Major General Roy S. Geiger, USMC (18 Jun thru 23 Jun)
General Joseph W. Stilwell, USA (from 23 Jun)
III Amphibious Corps (Embarked in Task Force 53)
Major General Roy S. Geiger, USMC
Chief of Staff: Brigadier General Merwin H. Silverthorn, USMC
Chief of Corps Artillery: Brigadier General David R. Nimmer, USMC
XXIV Army Corps (Embarked in Task Force 55)
Major General John R. Hodge, USA
Lieutenant General Mitsuru Ushijima (seppuku 22 June)
Approx. 67,000 men under arms, incl. 5,000 Okinawan conscripts[5]