scipian
Czar
Way back in Civ. III I had a pretty bad incident. There were two continents. I, the Babylonians and Viking (?) were the big three with two smaller nations. The Vikings and I were alone on our continent. I was on good terms with the Babylonians and was planning a HUGE attack. We each had 30-40 cities. Well, I pulled most my troops to the Viking border. I declared war. I was winning, even though I had badly miscalculated their strength. Then the Babylonians launch a huge attack on my coast cities. My huge, wonderful, wonder filled cities... So I set my men up on defensive on the Viking border and charge to defend my cities. Then the Vikings showed their true strength and launched a huge invasion. I decided to resolutely draft everyone I could and defend my center. I couldn't and lost. And that was on a pitifully low level. 

Only AI though 
I thought it was way harder than this