I've just finished a game...and won a Science Victory as the Byzantines, where I was at war with Germany...from very near the beginning...Germany was the the runaway civ....far stronger militarily, but I was able to destroy wave after wave of attacks with an Archer which gradually got stronger...progressing to Crossbow...Gatling Gun... Machine Gun...with extra range and logistics...
But his peace terms were always ridiculous... I was even able to capture two of his smaller cities once I had artillery and a few horse units... Eventually I gave into a lump sum payment, gold per turn, some luxuries, just to buy some time.
I then worked my strategy...I was close to Berlin and got closer with a couple of citadels.... Once I had rocket artillery and modern armour and a couple of Bombers... I "pounced"...I DOW'd and captured Berlin in two turns ...which ended his Space Ship program...then quickly captured two other medium size cities. I was merciless.. you get that way after a 1500-year war...
It was actually an exciting game...he had almost all of the CS's as allies...but his peace terms, except for the one I finally took, would have killed my game... What surprises me is how the AI are able to produce such a vast military...and sustain the loses.. I lost very few units in all of this, but the AI continued to believe it had me "on the ropes"....
But at least the game held my interest right to the end... It's interesting how these games can go...sometimes I've gone the entire game with no warfare; in other games..like this one...it's virtually continual warfare....but you have to keep trying...somehow with this game, I knew I had a chance...not a guarantee, but a chance, at ultimate victory...