The year 1945 saw the execution of three of the Marine Corps' largest and most vicious battles - Peleliu, Okinawa and Iwo Jima - and the Marines' performance in these arenas reflected the massive changes that had taken place in the Corps over the preceeding four years. These battles, the recent re-organisations, new units and weapons systems were intended to prepare the Marines for the planned invasion of Japan in November 1945. In this companion volume to Order of Battle volumes 1 and 7, Gordon Rottman studies this re-organisation in detail, discussing new assault units, provisional combat support groups, and service units.