What was the attack of Frederick called?

Battle of the Windmill

The events of Chapter VIII cover the historical events of: Hiter’s ascension to power in Germany, the Nazi-Soviet non-aggression pact, and Germany’s invasion of the Soviet Union. Napoleon continues to be suspicious of Frederick just as Stalin kept one eye open as Hitler ascended to power in Germany. The stories of animal torture on Frederick’s farm are meant to symbolize the reports of atrocities coming out of Nazi Germany. The rumors are not substantiated in Animal Farm, presumably because the truth about the scale and severity of Hitler’s atrocities did not emerge fully until after World War II. Napoleon’s tightening leash on Animal Farm’s consciousness is reflected in his interactions with the messenger pigeons. The pigeons, which were formerly his mouthpieces, are now forbidden from flying over the neighboring farms. Presumably, Napoleon does not want them to undermine his ever-changing opinions about Frederick and Pilkington.