The text starts from the description of the Manor farm and Mr. Jones, the farm owner, who is a cruel and cynical man. He butchers the farm animals and kills the dogs when they grow too old. He exploits everyone on the farm to death and is a heavy drinker. The life looks extremely bleak for farm inhabitants.
Once, a pig, called Old Major gathers everyone in the barn and starts his speech. He says that life is unfair to them, they live in poverty and slavery they do not deserve, while the human uses them as he pleases. Old Major calls everyone to revolt against the human tyranny and build a new society where every animal will be equal and will have a happy life. Mayor starts singing an old song “The beasts of England”, other animals join and it becomes the anthem of the resistance.
But eventually, Old Mayor dies a few days later, leaving nothing but a beautiful idea of utopia. To make it come to life and maintain a fair society, his most devoted followers, pigs named Snowball, Napoleon and Squealer, develop a philosophy called Animalism. This philosophy is based on seven commandments:
1. Whatever goes upon two legs is an enemy.
2. Whatever goes upon four legs, or has wings, is a friend.
3. No animal shall wear clothes.
4. No animal shall sleep in a bed.
5. No animal shall drink alcohol.
6. No animal shall kill any other animal.
7. All animals are equal.
For those animals who were not able to comprehend all the seven commandments there was a simplified version: “Four legs good, two legs bad”. The pigs, who are considered the smartest of all, start the preparations for the revolution. The most faithful apprentices of them are two cart-horses, Boxer and Clover.
The resistance turns out even more successful than they thought. Jones gets drunk again and his workers abandon the animals. Facing the starvation, the farm inhabitants overthrow the human “government” of the farm with overwhelming rage and courage and set up their own society living to Animalism laws. They change the name of the farm from “Manor farm” to “Animal farm”. The animals destroy everything that reminds of human rule, leaving just the Jones’ house as a museum, but no one is allowed to live here. They also write down the commandments of Animalism on the barn wall, so that anybody can read them and live by them.
Animals work hard, but they are happy building a new fair society. Boxer is the hardest worker of all, he wants to work even more every new day. Every Sunday all animals gather to vote and discuss new decisions and to sing “The beasts of England”. But pigs are the only ones who suggest the decisions, others just vote. No one is surprised, because pigs are still known to be the smartest, they are also the founders of Animalism ideology. So animals suppose they know better. Also pigs never do the actual work, they are only giving commands to others.
Jones and other men try to attack the farm and return the control, but animals unite and fearlessly fight back, forcing humans to retreat. Farm inhabitants are proud and call this fight “The Battle of the Cowshed”. They establish new military medals and honor the war veterans Snowball and Boxer.
Snowball and Napoleon are constantly arguing on every Sunday gathering and this argues put a strain between them. The most discussed topic is the building of the windmill. Snowball engineers everything needed and plans to attach a generator to it and electrify all the farm. Napoleon objects this idea, but when Snowball convinces other animals to vote for it, Napoleon brings nine vile dogs to the farm and they attack Snowball. Snowball barely escapes and runs away from the farm to be never seen after that.
Napoleon dismisses the gathering and forbids any other votes. Every issue is now the business of the special committee consisted of pigs only. Any animals that dares to criticize the new politics now shall face the dogs. Boxer decides that everything that Napoleon tells is truth and chooses a new motto for himself: “Napoleon is always right”.
With the help of the younger but silver-tongued pig, Squealer, Napoleon claims that it was his idea to build the windmill all along. Snowball stole it and tried to convince everyone that the idea was his. Napoleon had no other choice than to oppose Snowball just not to let the evil triumph. One night a huge explosion destroys the unfinished windmill that was built by Napoleon. Napoleon accuses Snowball and starts the “investigation”. He gathers all the animals and chooses some who, according to his words, were connected with Snowball and the dogs kill them. Shocked animals start singing “The Beasts of England” but Napoleon forbids the anthem and changes the sixth commitment. Now it says that no animal shall kill any other animal without a reason, and treason and terrorism are, obviously, reasons. Now everything that goes wrong is the fault of Snowball sneaking around and searching for new ways to destroy the farm. Every time new “allies” of Snowball are found and eaten by the dogs. Sometimes they are just bystanders, but usually they are the ones who have disagreed with Napoleon. Another pig called Minimus creates the new anthem of Animal farm and some other songs praising Napoleon.
Mr. Frederick, the neighbour of the Animal Farm and owner of Pinchfield farm briefly makes an alliance with Napoleon but suddenly decides to attack him. In the battle the newly built windmill is completely destroyed with blasting powder, lots of animals are killed and wounded, but they manage to survive this attack. The consequences are devastating. Still, Napoleon’s inspiring speech make animals feel proud and consider this battle their biggest victory.
The time passes. Almost all the commitments change slowly, assuring the privileges of pigs. Boxer becomes old and sick because of his exhausting work. Napoleon ruthlessly sends him to be slaughtered - despite all his devotion and battle medals he is useless now. Napoleon claims that Boxer will be taken to the veterinary. One of the farm inhabitants, the cynical donkey Benjamin sees that the van that took Boxer belongs to the knacker. He tries to rescue Boxer but Squealer convinces him that everything is fine and the van was just bought by the clinic. The truth is that Napoleon sold his most loyal and devoted worker for money to buy himself more whiskey.
There are less and less animals who still remember the life before the rebellion. The farm becomes more prosperous but all income is divided between pigs and dogs, any other animals shall work hard for living. They starve, drink dirty water, suffer from cold and heat. Squealer makes new reports and diagrams, proving that life on the farm is much better than before and everyone believes him. Some animals still remember something about initial commitments and ideas though, but they are either too tired or too frightened to speak up. Clover, the second cart-horse and the partner of deceased Boxer, understand that something is wrong, but she isn’t smart enough to express herself clearly and ends blaming herself for not remembering the commandments correctly. But mostly animals are proud: they own the unique farm where animals have the equal rights, are free and work together for the common good.
Meanwhile pigs move to the Jones’ house (the former museum) and sleep in beds, changing the fourth commitment to “No animal shall sleep in a bed with blanket”. Napoleon has a separate room and uses the human tablecloth. Pigs start trading with humans, they drink whiskey and beer the other animals brew for them. The last and most important commitment becomes “All animals are equal, but some are more equal than others”. Pigs start walking on two legs and wear old Jones’ clothes. Two legs now become better than four.
People from other farms visit Animal farm. Other animals look through the window and see that pigs and humans drink alcohol and play cards talking about friendship and common business. Napoleon shows the document stating that the farm is now the property of pigs and is called Manor farm again. Then pigs and humans get even more drunk and start to argue, then the fight starts and no one can distinguish pigs from humans.