Along the way, Reynolds shows, Churchill had to bend and sometimes break the historical record - for instance, by overstating his support for a cross-channel invasion.

The cross-channel invasion had already been postponed until 1944, and the main Allied push that year was toward southern europe.

The centrepiece was Operation Starkey, which included a major bombing campaign prior to a cross-channel amphibious "invasion".

She remained at Plymouth throughout April and May readying herself for "Operation Overlord", the long-awaited, cross-channel invasion of Europe.

This was not a force that could contest the command of the Channel to cover a cross-Channel invasion, and in this way the Norwegian campaign probably helped save Britain.

Britons believed they knew better than Americans the formidable hazards of a cross-Channel invasion against entrenched German defenders commanded by Rommel.

The cross-channel invasion of France finally came on 6 June 1944, Operation Overlord, the invasion of Normandy.

Allied victory in North Africa in May 1943 had left powerful forces in the Mediterranean theatre, and it was too early to use them in a cross-channel invasion of Europe.

Calling Italy the "soft underbelly" of the Axis, Churchill had therefore advocated this invasion instead of a cross-channel invasion of occupied France.

Another major German missile development project was the anti-shipping class (such as the Fritz X and Henschel Hs 293), intended to stop any attempt at a cross-channel invasion.