Mr. Jones the farmer is a drunk and cruel tyrant, and one day the animals on his farm have had enough of him, so they take over the farm and kick him out. They set up a government of their own. It starts out as an egalitarian government, where all animals are equal, but as time progresses it turns into a regime as repressive and totalitarian as that of Mr. Jones. Their new motto is "All animals are equal, but some are more equal than others." In the end they become a drunk tyrant just like Mr. Jones, so the revolution was not revolution at all.