This is the tale of three Australian bomber squadrons at war, flying with RAF Bomber Command in the early part of Britains bombing offensive upon Nazi Germany, from August 1941 to September 1942. Nos 455, 458 and 460 Squadrons operated Hampden or Wellington twin-engine bombers from bases in Yorkshire or Lincolnshire, flying impossible missions, using inadequate equipment and navigation methods to try to hit the most formidably defended targets in the world. It provides the first ever detailed combat history of these three squadrons in their initial incarnations, using original sources. This campaign saw the only major and ongoing Australian contribution to the war against Hitlers Germany. It was proportionally the bloodiest in Australian and British military history, with the survival rate among the aircrews dropping by Autumn 1942 to about 25 percent. Themes include: The Australianisation process by which Australian personnel were brought in by the RAAF to gradually turn what were essentially British units into almost fully Australian ones. The gross inefficiency of bombing in general, and of early-war bombing in particular. The terrifying and brutal nature of World War II air warfare, as experienced by the airmen. The tragic fates of aircrew. The moral and existential quandaries faced by combat leaders. The resilience of the bomber squadron as a social organism which maintained enough morale for most men to carry on, despite the unit being turned into a veritable revolving door -- with new crews arriving from training units as fast as the older crews were shot down. The gradual emergence of more rational and effective methods to the RAFs bombing war, preconfiguring the methods it would use with much greater success through 1943-45.