Mr. Frederick owns Pinchfield, one of the neighboring farms to Animal Farm. From the start, he is described as “a tough, shrewd man, perpetually involved in lawsuits and with a name for driving hard bargains” (4.2). Frederick, like many of the minor allegorical characters in Animal Farm, is paper-thin. His role in the story makes much more sense when you realize that he is a stand-in for Adolf Hitler, and for the Nazi Party in general.
Initially, Frederick, like Pilkington, is worried about the Rebellion on Mr. Jones’s farm. He suspects that such revolutionary ideas may spread to his own animals. He thus makes sure to spread rumors that the “animals there practiced cannibalism, tortured one another with red-hot horseshoes, and had their females in common” (4.3). Relations with Frederick continue to be hostile for much of the story, and Squealer is supposed to spread the rumor that Snowball is conspiring against Animal Farm with Frederick.
Yet Napoleon makes an unexpected reversal late in the story. He has a pile of timber that he needs to sell, and after promising it to Pilkington, he suddenly switches and decides to sell it to Frederick. He has Squealer explain that he was playing the two farmers off against one another in order to drive up the price of the timber. But it turns out that Frederick has a trick up his sleeve. Mr. Whymper comes running back to tell Napoleon, “The bank-notes were forgeries! Frederick had got the timber for nothing!” (8.14).
The above episode is an allusion to the broken non-aggression pact that Stalin signed with Hitler in 1941. The pact allowed Soviet Russia and Nazi Germany – which had been bitter enemies up to that time – to divvy up Eastern Europe into respective spheres of influence. (Too bad for the poor people of Eastern Europe, now doomed to domination by one totalitarian regime or the other.) The prospect of any kind of alliance, or even state of non-aggression, between Stalin and Hitler was seriously worrying to Great Britain, which was struggling for survival in a lonely war against Germany on the Western Front through most of 1940 and 1941. (France fell to German attack in June 1940, and the United States didn't enter the war until December 1941.)
But the Nazi-Soviet agreement didn't last. Just like Mr. Frederick, Hitler broke the pact. In 1941, Germany launched Operation Barbarossa, launching a massive surprise attack into Soviet territory and starting the war on the Eastern Front. By December of 1942, German troops had pushed within 20 miles of Moscow. The war's bloodiest fighting occurred on the Eastern Front, with millions of German and Soviet soldiers losing their lives in a desperate struggle to finish off their opponents. After holding onto the strategically significant city of Stalingrad through the winter of 1942-43, the Soviet Red Army began pushing the Germans slowly back toward the west. The tide of the war had turned, but it would take another two years of brutal combat to bring it to an end.
In Animal Farm, we have a miniature version of the war on the Eastern Front in the Battle of the Windmill. Frederick and his men advance quickly and blow up the windmill, but they are ultimately repelled. After that, Frederick disappears from the story.