Have you ever lost a campaign?

[Hellenic_Hoplite]

the only time I can really think of is when I was playing as macedonia on rtw and had to face the insanly powerful roman units, I remember I kept sending armies of royal pikemen over to rome only to have them be decimated by legionarries (is that how you spell it), I eventually abandoned that campaign.

[magnum]

Not many but have lost a few that either luck was against me (yea, it was all bad luck, thats what it was!) or I simply badly mismanaged my empire.

[Rebellious Waffle]

I haven't run a campaign long enough to lose. Farthest I ever got was around turn 50, with the Holy Roman Empire. Conquered the Levant region on Crusade, donated it to the Pope, consolidated my crusading armies and cut a bloody swath through Asia Minor in the name of the See of Rome.

(The Papal States became the second most powerful faction, next to me -- I wasn't interested in Asiatic holdings because of the potential for Mongol problems later. Sack the cities, make off with the gold, donate the ruins to the Papal States, merge armies and buy mercenaries as you savage Egypt, Turkey and Byzantium. When the Mongols invade, my plan was to turn my armies around and start killing barbarians, redonating the conquered lands as I go. When the Timurids invaded, I planned on sticking around; why go to all the bother of holding that land when I can plunder it and let someone else pay the construction costs? Besides, they make reliable bribes against excommunication.)