How did Napoleon keep his power?

Napoleon didn't play a large part in the in the initial rebellion. He, however, ascends to power quite quickly. He is one of the more intelligent pigs using manipulation and force to control and eliminate opposition. Much like Joseph Stalin, Napoleon has a "secret police" or henchmen to enforce what he wants. Actually they were more like "Hench dogs". Napoleon takes nine puppies from their parents and begins raising them himself. No one knows exactly what he is doing until the dogs suddenly appear, fully grown, to chase Snowball off the farm. Snowball, a fellow pig, was Napoleon's biggest critic. In the end Napoleon was a bully. He was a, "the only Berkshire on the farm, not much of a talker, but with a reputation for getting his way”. Much like Stalin, Napoleon protects himself on all fronts. With the help of Squealer and the other pigs, he re-writes history.