Old Major, the old boar on the Manor Farm, summons the animals on the farm together for a meeting, during which he refers to humans as parasites and teaches the animals a revolutionary song called Beasts of England. When Major dies, two young pigs, Snowball and Napoleon, assume command and consider it a duty to prepare for the Rebellion. The animals revolt and drive the drunken and irresponsible farmer Mr. Jones from the farm, renaming it "Animal Farm". They adopt Seven Commandments of Animalism, the most important of which is, "All animals are equal."
Snowball teaches the animals to read and write, while Napoleon educates young puppies on the principles of Animalism. Food is plentiful, and the farm runs smoothly. The pigs elevate themselves to positions of leadership and set aside special food items, ostensibly for their personal health. Napoleon and Snowball struggle for preeminence. When Snowball announces his plans to build a windmill, Napoleon has his dogs chase Snowball away and subsequently declares himself leader of Animal Farm. [Taken from Wikipedia]