A pig in the farm, Old Major, was dead after he put forward the theory of "Exploiting by human, the livestock must have revolution". After a number of years, there was a revolution in the farm led by the pig, the original exploiters - the farmer, had been drove out. The livestock achieved the goal of the revolution, the farm changed its name to "Animal Farm", and the Constitution of the farm was established - Seven Commandments.

But not long afterwards, the leaders of the revolution broke up, a pig was declared to be the enemy of the revolution. Afterwards, the pig leader became more and more powerful and got more and more special treatment, he gradually deviated from other animals, and evolved into the animal exploiters exactly the same as human eventually. The name of Animal Farm had also been abandoned.