Simon Bolivar Buckner Jr. was a major figure of the Pacific War, both for his command in Alaska and in his key role heading Tenth Army during the Battle of Okinawa in the spring of 1945. Buckner was the senior U.S. officer killed by enemy fire in World War II when Japanese artillery cut him down on June 18, 1945, one month shy of his 59th birthday. The shelling ended a remarkable life – son of a Confederate Lieutenant General and governor of Kentucky, the "Child of the Democracy" in the 1896 Presidential election campaign, educated at West Point, myriad service as a student and instructor at various Army posts and schools from 1917 to 1936, command in Alaska from 1940 to 1944, and ultimately of Tenth Army from 1944 to his death. General Buckner kept a diary covering the period from January 1, 1944 to June 17, 1945, which has never been fully published until now. Buckner made notes every day, often in great detail; his chief of staff thought Buckner wanted to write a memoir after the war, but the papers were scattered after his death. In addition to the Okinawa material, Buckner's diaries discuss his departure from Alaska and service in Hawaii as Tenth Army commander. Topics include his daily life in wartime Hawaii, troop training, comments on war events, gossip, notes on his travels to Guam and the Philippines, and his role in the Smith vs Smith controversy after the Battle of Saipan. The diary text is augmented by letters from General Buckner to his wife Adele during March to June 1945, and a letter from the Tenth Army Chief of Staff to Adele detailing Buckner's death. Tenth Army Commander is an important account from a too-long-silent voice among Pacific War leaders.