Old Major called the animals into the barn to discuss the dream he had about revolting against the owner of Manor Farm and the unfair conditions he put the animals in. After Old Major died, the animals took the farm for themselves and started to create a government that was to benefit them and keep humans away.
As the animals began to educate themselves, mostly to be able to understand the 7 commandments of Animalism, it was determined that the pigs were the smartest. As the farm kept running smoothly, tensions arose between the pigs as they wanted to become the sole leader of all the animals. Napoleon ended up running snowball off the farm and winning the spot as leader.
Napoleon becomes the supreme leader and makes many changes, such as agreeing to build a windmill and creating a committee for the pigs to discuss farm activities. He uses Squealer to manipulate the animals into thinking that Napoleon is always right and could do no harm. As Napoleon made more changes and became addicted to leading, he was paranoid that his power would be taken away from him.
Snowball is constantly used for a scapegoat in response to all of the incidents, such as the windmill being destroyed, and Napoleon convinces everybody that Snowball is not the nice and courageous pig everybody thought he was. Napoleon even began to kill animals who he thought was siding with Snowball and the humans, which shocked all of the animals watching.
The animals begin to see that Napoleon is controlling them more than they'd like. He is breaking the rules and becoming more separate from the rest of the animals. They wonder if this was the rebellion that Old Major was talking about.
It is made clear that the animals are no longer equal. The pigs put themselves above everyone else and begin to do things that were associated with human activity. It becomes clear that humans and pigs are very alike.