Old Major, the old boar on the Manor Farm (or "Willingdon Beauty" as he is called when he is exhibited) calls the other animals on the Farm for a meeting, where he compares the humans to parasites, and then proceeds to teach the animals a revolutionary song: "Beasts of England."
When Major dies three days later, two young boars - Snowball and Napoleon - assume command, and turn his dream into a full-fledged philosophy. The animals revolt and drive Mr. Jones from the farm, renaming it "Animal Farm."
The Seven Commandments of Animalism are written on the wall of a barn for all to read. The most important is "all animals are equal." All animals work, but the workhorse, Boxer, does more than others and adopts the maxim — "I will work harder."
Snowball teaches the other animals to read and write (though few besides the pigs learn to read well), food is plentiful, and the entire farm is organized and runs smoothly. Meanwhile, Napoleon takes the pups from the farm dogs and trains them privately. When Mr. Jones tries to retake the farm, the animals defeat him at what they call the "Battle of the Cowshed." Napoleon and Snowball begin a power struggle for leadership. When Snowball announces his idea for a windmill, Napoleon quickly opposes it. Snowball makes a passionate speech in favour of the windmill, then Napoleon summons his nine attack dogs, which chase Snowball away. In Snowball's absence, Napoleon declares himself leader and makes changes. Meetings will no longer be held because a committee of pigs alone will decide what happens with the farm.
Screenshot from Animal Farm (1954 film)Napoleon, using Squealer as a mouthpiece, announces that Snowball stole the idea for the windmill from him. The animals work harder with the promise of easier lives with the windmill. After a violent storm, the animals find the fruit of their labor annihilated. Though neighboring farmers scoff at the thin walls, Napoleon and Squealer convince everyone that Snowball destroyed the windmill. Once Snowball becomes the scapegoat of the story, Napoleon begins to purge the farm, killing many animals he accuses of consorting with Snowball. Meanwhile, Boxer takes a second mantra, "Napoleon is always right."
Napoleon abuses his powers, and life becomes harder and harder for the animals; the pigs impose more and more controls on them while reserving privileges for themselves. The pigs rewrite history to villainize Snowball and glorify Napoleon(i.e stating that Snowball fought for the humans in the Battle of the Cowshed, and that Napoleon bit Snowball, when Snowball was actually hit by a pellet from Jones' gun.) Squealer justifies everything, even the occasions when the pigs alter the Seven Commandments— for example, "No animal shall drink alcohol" becomes "No animal shall drink alcohol to excess." The song "Beasts of England" is banned as inappropriate (as the dream of Animal Farm has been realized), and is replaced by an anthem glorifying Napoleon, who begins to live more and more like a human. The animals, though cold, starving, and overworked, remain convinced that they are still better off than when they were ruled by Mr. Jones, the previous (human) owner of Manor Farm. Squealer abuses the animals' poor memories and invents numbers to show their improvement.
Mr. Frederick, one of the two neighboring farmers, swindles Napoleon by buying lumber, and then attacks the farm, using blasting powder to blow up the recently restored windmill. Though the animals of Animal Farm eventually win the battle, they do so at a great cost, as many of the animals, including Boxer, are wounded. (Squealer, however, was mysteriously absent from the fight). However, Boxer continues to work harder and harder, until he finally collapses while working on the windmill. Napoleon sends for a van to take Boxer to the veterinarian, explaining to the worried animals that better care can be given there. However, Benjamin notices as Boxer is loaded up that the van really belongs to "Alfred Simmonds, Horse Slaughterer and Glue Boiler", but the animals' last desperate attempts are futile. Squealer quickly reports that the van with the old writing had been purchased by the hospital and had simply not been repainted yet. He then recounts a dramatic and tear-felt tale of Boxer's death in the hands of the best medical care. In reality, the pigs sent Boxer to his death in exchange for more whiskey.
Many years pass, and the pigs learn to walk upright, carry whips, and wear clothes. The Seven Commandments are reduced to a single phrase: "All animals are equal, but some are more equal than others." Napoleon holds a dinner party for the pigs and the humans of the area (in the adjacent Foxwood Farm, run by Mr. Pilkington), who congratulate Napoleon on having the hardest-working animals in the country on the least feed. Napoleon announces his alliance with the humans, against the labouring classes of both "worlds". He then abolishes practices and traditions related to the Revolution, and renames the farm "the Manor Farm".
The animals, overhearing the conversation, notice that the faces of the ruling pigs have begun changing. During a poker match, an argument breaks out between Napoleon and Mr. Pilkington when they both play the Ace of Spades, and the animals realize that the faces of the pigs now look almost exactly like the faces of humans and they can no longer easily tell the difference between them.