Animal Farm opens on Manor Farm, where Mr. Jones, the neglectful owner, drunkenly shuts the animals away and goes to sleep. The animals gather in the barn to hear a boar named Old Major share his dream of a world ruled by animals instead of humans. Old Major blames humans, especially Mr. Jones, for the animals’ suffering, saying that humans exploit and kill animals when they are no longer useful. He urges the animals to overthrow humans but warns them never to imitate human behavior or treat each other unequally.

The Rebellion Begins

Three days after Old Major’s speech, he dies, and the animals start preparing for rebellion. Led by two pigs, Snowball and Napoleon, and aided by the persuasive pig Squealer, they create the philosophy of “Animalism.” The rebellion comes sooner than expected when Mr. Jones neglects to feed the animals and then attacks them. The animals drive Mr. Jones off the farm and rename it Animal Farm. They establish seven commandments based on Old Major’s principles:

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.

Early Success and Power Struggles

The animals work hard to prove their independence. The pigs quickly assume leadership roles, justifying their superior rations by saying they need the extra energy for management duties. When Mr. Jones attempts to retake the farm, the animals, led by Snowball’s military strategy, win what they call the “Battle of Cowshed.”

However, a rivalry grows between Snowball and Napoleon. Snowball organizes animals into committees and teaches them to read, while Napoleon focuses on training a group of young puppies in secret. The two clash over a windmill project: Snowball believes it would make farm life easier, while Napoleon argues it would lead to starvation. Just before a final vote, Napoleon’s trained dogs chase Snowball off the farm, leaving Napoleon in control.

Napoleon's Rule

With Snowball gone, Napoleon declares that Sunday meetings are abolished and that all decisions will be made by a committee of pigs. Soon after, he reverses his stance on the windmill, claiming the idea was his all along. Under his rule, life on the farm deteriorates, with rations shrinking as the animals are made to work harder on the windmill.

Napoleon starts trading with neighboring human farms, which makes the animals uneasy. To justify these actions, Squealer adjusts the commandments, for instance, altering the one on sleeping in beds to “No animal shall sleep in a bed with sheets.” Meanwhile, the pigs spread rumors that Snowball is plotting to sabotage the farm, blaming him for every mishap.

Hardships and Executions

Food shortages grow severe, and the hens rebel when Napoleon tries to sell their eggs. The rebellion is quickly crushed, and Napoleon holds a public meeting where several animals confess to crimes they supposedly committed with Snowball. They are promptly executed, and the commandment against killing is revised to “No animal shall kill any other animal without cause.”

Napoleon also manipulates neighboring farmers to get a better deal for timber, but Mr. Frederick eventually pays him with counterfeit banknotes. Enraged, Napoleon discovers Mr. Frederick has attacked the farm and destroyed the windmill. The animals barely fend him off, and after the battle, the pigs find whiskey, prompting a revision of the commandment on alcohol to “No animal shall drink alcohol to excess.”

Boxer's Fate and the Rise of the Pigs

Boxer, a loyal and hard-working horse, sustains a severe injury while working on the windmill. Napoleon claims he will send Boxer to a hospital, but the animals see a van labeled “Horse Slaughterer and Glue Boiler” take Boxer away. Squealer later convinces the animals that it was a misunderstanding and Boxer died peacefully at the hospital.

The pigs increasingly mimic humans, using their position to privilege themselves. They begin wearing human clothes, walking on two legs, and even enforce a rule that animals must yield the path to pigs. They replace the commandments with a single phrase: “ALL ANIMALS ARE EQUAL BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS.”

The Farm’s Return to "Manor Farm"

One day, the animals witness Napoleon hosting human farmers. The pigs and men celebrate Animal Farm’s success in making animals work hard for minimal food. Napoleon then announces that Animal Farm will return to its “correct” name: Manor Farm. As the animals look through the window, they realize that they can no longer distinguish the pigs from the humans.