In May 1940 Nazi Germany was master of continental Europe. The only European power still standing was Great Britain--and the all-conquering German armed forces stood poised to cross the Channel. After the RAF fighter forces had been destroyed, the Channel swept of mines, and the Royal Naval defenders worn down, two German army groups were set to storm the beaches of southern England. Despite near-constant British fears from August to October, the invasion never took place, first being postponed to spring 1941 before finally being abandoned entirely.

Robert Forczyk, author of Where the Iron Crosses Grow, looks beyond the traditional British account of Operation Sea Lion, complete with plucky Home Guards and courageous Spitfire pilots, at the real scale of German ambition, plans and capabilities. Forczyk examines, in depth, how Operation Sea Lion fitted in with German air-sea actions around the British Isles as he shows exactly what stopped Hitler from invading Britain.