The story begins with Old Major making an announcement to the other farm animals at Manor Farm. He says that the animals must rebel because they have been mistreated by humans for far too long. At the end, he recalls a dream he had where he remembered a song from his childhood, Beasts of England.
A few days later, Old Major dies, but the other animals still want to rebel. Over the next few months they plan for the rebellion to happen. Then, one day, when Mr. Jones is coming back to the farm with friends, the animals attack. They successfully take over the farm.
A few months later, Jones returns to attempt to take back the farm. However, the animals are prepared as well. Snowball sends out a small number of animals to start the battle, making the humans think that they are victorious when they can easily defeat their enemies. Then, Snowball sends out a much larger group of animals, and they successfully defend Animal Farm. At the end of the chapter, the animals finally decide to name this battle the Battle of the Cowshed.
Snowball is chased off the farm after arguing with Napoleon about the windmill. Napoleon, as the new leader of the whole farm, changes rules and decides that the windmill should be built. He also changes some of the Commandments. In Chapter 8, the animals fight the Battle of the Windmill against some farmers. During the battle, the farmers blow up the windmill that the animals had been working on for 2 years.
One day Boxer collapses while working. Napoleon decides that he will be taken to a hospital to be treated. When the van arrives and drives away with Boxer, Benjamin reads the side and realizes that Boxer is being taken to a horse slaughterer. The animals yell at Boxer to escape, but he does not make it. After it is announced that Boxer has died, Napoleon claims that he was actually treated and that the van only said "Horse Slaughterer" because that was the previous owner's job. The pigs also continue to buy whiskey.
Boxer! Get out!
Years have passed. One day, the animals are working outside when they see the pigs standing on their hind legs. They are shocked. Clover, whose sight is failing, then asks Benjamin to read what the Commandments are. They have been reduced to one single commandment: "All animals are equal, but some animals are more equal than others". A week later, the animals look into the farmhouse one evening and see the pigs playing poker with humans. A disagreement occurs between Napoleon and Mr. Pilkington. As the animals watch them fight, they cannot tell the pigs and men apart.