How is the history of the Battle of the Cowshed rewritten in animal farm?

In George Orwell's "Animal Farm," the history of the Battle of the Cowshed is rewritten to glorify Napoleon's leadership and diminish Snowball's contributions. Initially, Snowball is portrayed as a heroic figure who strategizes the defense against the humans, but later, he is scapegoated and labeled a traitor. The pigs manipulate the narrative to emphasize their own importance, presenting Napoleon as the sole hero of the battle, thus altering the past to consolidate power and control over the other animals. This revisionism reflects the broader theme of how those in power can manipulate history for their own ends.