What would have happened if Germany had invaded Britain?

Than there would be more chance of the Nazis conquering all of Europe unless there are other forces to stop them.

Or one could posit that they actually, in fact, lost WWII.

The US won, as the war catapulted it into world military and economic superpower status.

The USSR won, as through the war, they gained hegemony over all of eastern europe, as well as became a global superpower.

But Britain; who's casus belli was to protect Polish independence; who's empire spanned to every corner of the world at the wars outbreak; lost much of its empire within three years of the wars end, mostly due to bankruptcy caused by the war. As a direct result of WWII, Britain was forced to depend on the US to protect it from the Soviets for fifty years after. And at the end of the war, Poland was turned into a Russian puppet state anyway.

So did Britain really win? Not by my count, though they were on the winning team.

Ergo non mutatio