Animal Farm sported its ideals of "equality," but this was not necessarily the case. They used to have a code of law written on the side of the barn. It promoted the principles of the Animalism that Old Major wished for. However, it was later replaced with one statement:.
"All animals are equal, but some animals are more equal than others.".
This statement summed up what the true intentions of the pigs were. They didn't seek for equality; they sought after their own personal benefit with the expense of the other animals" welfare.
The inequality began from the start, except with lesser benefits and more believable lies. The first occurrence was when they found that the milk was missing. The pigs defended themselves by saying that they needed it because it provided the essential nutrients to supply energy for thinking since they did no physical work on the farm. They used the same argument for the missing apples afterwards. They made the animals believe that if they did not get their milk and apples, then Mr. Jones would return. This idea became ingrained into their minds even after they completely forgot about the days before the revolution. The pigs were beginning their infection of the vulnerable minds of the animals.
The inequality began to increase at a much more drastic rate when Snowball was exiled from the farm. Napoleon began to use a "secret police" that were used for terror and removing those who opposed him. He began the construction of the windmill which led to increases of backbreaking labor upon the animals. Napoleon's greed was ever increasing and was not ceasing. He slowly increased the workload and the work hours. The food supplies for the working animals were intensely severed. He applied more force onto the working animals for the increasing benefit of the non-working pigs.
.
Napoleon, near the end of the book, became a very cruel tyrant who ruled as mercilessly as other farmers.