The animals on Manor Farm take over, vowing to forbid any contact with humans, whom they see as immoral enslavers. However, as the story progresses it is very obvious that the virtues that started the revolution have been perverted.
The book is largely a satire of the Russian Revolution. The pig, Old Major, who first comes up with the idea of Animalism, is based on Karl Marx. Snowball the pig, an early leader of the revolution before he is accused of treason and driven into exile, is based on Leon Trotsky. The pig Napoleon who takes over the farm, lives in luxury and imposes his will on all the animals through fear and intimidation, is based on the Soviet dictator Josef Stalin. Boxer the horse represents the workers of Russia.
Animal Farm tells the story of the animals of Manor Farm who have been mistreated by the farmer Mr. Jones, They begin to see hope for a brighter future when, shortly before he dies, one of the oldest animals, the pig Old Major, prophesies the overthrow of the human race and freedom for animals.
Mr. Jones repeatedly fails to feed the animals. The animals refuse to accept this any longer. They break into the food shed and gorge themselves. Mr. Jones and his men attempt to intervene, but the angry animals drive them away from the farm. The animals proceeded to destroy almost everything that reminds them of the humans. However, the house is left unchanged. It is decided that no animal is to live in the house and it is to be be kept as a museum. The animals change the farm's name from Manor Farm to Animal Farm.
A set of laws, called the Seven Commandments, are set up which all the residents of Animal Farm have to follow. They are: .
- Whatever goes upon two legs is an enemy.
- Whatever goes upon four legs, or has wings, is a “friend”.
- No animal shall wear clothes.
- No animal shall sleep in a bed.
- No animal shall drink alcohol.
- No animal shall kill any other animal.
- All animals are equal.
Most of the animals have poor memories, which is why the pig Snowball summarizes the rules as “Four legs good, two legs bad”.
The pigs, being the most intelligent of the animals, automatically assume leadership. There is a power struggle between two pigs, Snowball and Napoleon. Snowball thinks that in order for the animals’ ideology to thrive it is necessary to start revolutions on other farms. Napoleon thinks the residents of Animal Farm should learn to use firearms to strengthen the farm from within.
Mr. Jones and other men come to take back the farm, but Snowball proves to be an expert tactician and defeats the invasion. Several animals and one human are killed in the Battle of Cowshed. After the unsuccessful invasion, the humans come to recognize the animals as the legitimate rulers of Animal Farm.
Snowball proposes the idea of making a windmill, he says that although it will take a lot of effort to make, it will generate electricity for the farm. Napoleon says that he is opposed to the idea. He uses his secret troop of viscious dogs to chase his rival away from the farm and denounces Snowball as a traitor. Napoleon accuses more animals of treason and orders them to be executed, violating the sixth commandment, “No animal shall kill any other animal”, Napoleon justifies his behavior by saying that the rule has in fact always been, “No animal shall kill any other animal, without cause.”
Napoleon surprises everyone by announcing that he was in support of windmill construction all along and that Snowball stole the plans from him. The animals begin the laborious task of constructing the windmill. The work is hard, but soon the building begins to take shape. One night, the animals all dream of a gunshot in the distance; they wake up to find their windmill in ruins. Napoleon proclaims that Snowball came in the night and destroyed the windmill. He orders him sentenced to death. However,the humans believe the windmill fell because the walls were too thin and a strong gale toppled it. The animals restart constructions and make the walls three feet thick instead of eighteen inches thick.
Napoleon announces they will sell some lumber to the farmer Mr. Frederick in order to raise money. The transactions go smoothly until the animals find out that Mr. Frederick is using counterfeit money to pay them. Napoleon sentences Mr. Frederick to death. Mr. Frederick and some other men come to invade Animal Farm; the animals fight fiercely but can not keep the humans away. Napoleon sends a pigeon to request help from the farmer Mr. Pilkington, but in reply Pilkington simply says “Serves you right”. The men come with explosives to blow up the windmill. Enraged at the destruction of the windmill, the animals attack and Frederick’s men retreat, but they suffer many casualties.
The horse Boxer, who is the hardest working of all the animals and one of the most loyal to Napoleon, becomes injured while working, Napoleon calls for a truck to take him away and explains later that Boxer was taken good care of but died anyway. In fact he was sent to the knacker's yard and made into dog food and glue.
Napoleon becomes increasingly human in his behavior and changes the saying “Four legs good, two legs bad” to “Four legs good, two legs better”. Eventually , the Seven Commandments are replaced by a single one: "All animals are equal, but some animals are more equal than others."
The last scene in the novel takes place many years later. Most of the animals who were alive at the time of the revolution have died but Napoleon and a few other pigs are still alive. Napoleon meets with Pilkington and other humans in the house. The pig announces that the farm is to return to its real name of Manor Farm. During a card game, Napoleon and Pilkington simultaneously play an ace of spades, and an argument errupts. The animals look into the house and can not tell pig and human apart.
- Text of George Orwell's Animal Farm on Wikilivres. The novel is in the public domain in Canada but is still under copyright in the United Kingdom and the United States.
- Quotations from and about Animal Farm on Wikiquote.
- Orwell's original preface to Animal Farm.