Wwii

8 years imposed war between us and whole of the world :exactly WWIII!

and maybe the great conquest of athen by achaemenian!

Every war is an important war to your country even more so if you lose it.
Now being a Brit lets have look at some the major conflicts that have have helped to change the world.
Stamford Bridge 1066
Hastings 1066
The Armada and the break from Rome
The defeat of Charles the first during the civil war here, for these battle really did change the world from being ruled from Rome and ridding our selfs of the restrictive thinking of a fanatical clergy.
Marlborough's victories over France.
The Defeat of Napoleon
WW1
WW2
To name but a few

For (almost) everyone its got to be WW2. Wars have changed nations throughout the ages but only WW2 would have ended with with worldwide domination by one nation.If Germany had won I wonder how long before there would have been a German empire v Japanese empire war?

What about the Armada then, if that had been successful Spain would have ruled the world, there would not have been an America as you know it, nor Canada, Australia or New Zealand. Holland would have still been under Spanish Rule along with France. People mainly think of the wars that still the closest to them, but really all wars are important and even more so if you lose them.

But going back in time is kinda pointless. What would of happend if hte neanderthols beat the cro-mangons!

The American Civil War easily. It was great and terrible; the death of democracy and the beginning of a great world power.

The American Civil War easily. It was great and terrible; the death of democracy and the beginning of a great world power.

The death of democracy? and the spanish american war set us on the path to becomeing a world power much more so than the Civil war. IMO

To me, it was Vietnam, because it gave us a kick in the butt as to our limits and strengths, as well as giving a good hard slap as to picking good presidents.

I would say the 80 years war when the Dutch republic fought against Spain from 1568- 1648. This war gave birth to our nation and the foundation of our monarchy. The whole constitutional mornarchy has been influenced by this war and the effects on how we run our nation is still felt.