The original Ogre Battle. In one of the bad endings, which you get if your Karma Meter is too far toward evil, your main character takes over the country instead of handing it off the the rightful ruler. The game then says that your main character was soundly and easily defeated within days. This occurs despite you having an army full of high level paladins, liches, and dragons at your command.
That's assuming they STAYED at your command, rather than joining the next rebellion.
The main character is often so powerful by the end of the game he could kill everyone else at once, making this one a particular wall banger for most players.
In the ending more close to this description, your character was not "soundly and easily defeated within days" but defeated in ONE YEAR with the implication that you was a hard opponent.