Having expected Mr. Jones to attempt to recover control of Manor Farm, Snowball has been studying a book of Julius Caesar’s battle strategies and has trained the animals in a series of defense strategies. We know the pigs are intelligent, having taught themselves to read, but it suggests a particular level of intellect that Snowball is able to understand and apply such military principles.

On October 12 the animals see the men coming down the road, Mr. Jones leading the way with a menacing gun in his hands. Rather than panic, the animals get into position under the guidance of Snowball. First he has the pigeons attack with excrement from overhead, while the geese bite at the men’s legs. Then the horses and sheep begin butting and kicking, “with Snowball at the head of them.” His bravery encourages the others to continue the attack.

Next, at a pre-planned signal from Snowball, all the animals retreat, leading the men into an ambush in the cowshed, where they all attack at once. Snowball himself goes for Mr. Jones, who shoots at him. In spite of bullet streaks wounding his back, the brave pig rushes at Jones, launching him into a pile of manure and knocking the gun out of his hands. At this all the animals attack in a frenzy, chasing the intruders off the farm for good.

When Boxer expresses sorrow, believing he has killed a stable boy, Snowball encourages them all to instead feel proud of their victory, stating that they should be willing to die for Animal Farm if necessary. In response the animals declare Snowball an “‘Animal Hero, First Class.’” Readers understand that Snowball is cunning and has his own agenda like the rest of the pigs, yet at this point in the story, he is clearly a leader willing to join ranks with his soldiers, not to merely give orders from a safe distance. This is also likely a main reason that Napoleon runs him off the farm, out of jealousy and hunger for total power. As a result, the animals will never get to know if life might have been better on Animal Farm under the leadership of Snowball.

At the Battle of the Cowshed, Snowball shows himself to be a leader of great competence and valor. Having learned a little about military strategy by reading a book about Julius Caesar's campaigns, he uses his expertise to come up with a battle plan. When Jones and the men attack, he orders a retreat. The animals' withdrawal turns out to be a ruse that leads the humans into a trap. Snowball himself shows considerable courage in leading the animals in a counterattack:

Snowball now gave the signal for the charge. He himself dashed straight for Jones. Jones saw him coming, raised his gun and fired. The pellets scored bloody streaks along Snowball’s back, and a sheep dropped dead. Without halting for an instant, Snowball flung his fifteen stone against Jones’s legs. Jones was hurled into a pile of dung and his gun flew out of his hands.

So Snowball is not only responsible for planning the battle, but he risks his own life to lead the animals to victory. After the battle, he, as well as Boxer, is decorated for bravery with the award "Animal Hero, First Class." After his falling out with Napoleon, however, Snowball leaves the farm, and Squealer goes to great lengths to rewrite the history of the battle, claiming that Snowball had no role in it. Indeed, he is later portrayed as having actually plotted with the humans to encourage the invasion in the first place. Snowball's role in the battle is analogous to Leon Trotsky's role in the Bolshevik Revolution and the Russian Civil War. Like Trotsky, he is forced to flee into exile.

Snowball masterminds the victory in this battle, which is a vitally important one for the animals against the human proprietor of the farm, Mr Jones. It is a very fierce battle with death and injury among the animals but Snowball in particular shows great courage in leading the defence.  After this battle, the farm belongs to the animals. This earns Snowball great honour and popularity but later he is demoted and eventually banished by his great rival for the leadership, Napoleon, and his crucial role in winning the farm for the animals is completely erased from the official record.

Napoleon resembles the ruthless Soviet dictator, Joseph Stalin, and Snowball can be compared to Stalin's early rival Leon Trotsky; their rivalry represents the power struggles following the Russian Revolution in the early 20th century.

Snowball's strategic prowess mirrors his Russian Revolution counterparts quite effectively. Trotsy was an incredibly strategic military leader who got the job done under Lenin as he was supposed to.

Likewise, Snowball's effectiveness earned him an honor among the animals: "Animal Hero, First Class." He also gave an inspirational speech that moved and motivated the animals. He spoke of the need for all animals to be willing to die for Animal Farm. At this point, Snowball appears an appropriate fulltime leader for the animals.

Snowball is the main leader of the animals' military defense in the Battle of the Cowshed.  This happens in Chapter 4.

In this chapter, we see that Snowball has learned a lot about leading military operations.  He apparently learned all of this from reading some old books about Julius Caesar's military campaigns.  He puts the information to good use.  He tells all the animals where to be as the battle is about to start.  And he is the one who orders the animals to attack when the time is right and when to pretend to retreat so as to trick the humans.

In George Orwell’s novel Animal Farm, Snowball (who is modeled on Leon Trotsky) plays some very important roles in the Battle of the Cowshed. This battle symbolizes the conflict, during but especially after the Russian Revolution, between the Bolsheviks and their opponents (and their opponents’ allies; for more on this matter, see the links below).

Snowball’s roles in the conflict are various and include the following:

• He is both a tactician and an effective military leader. When the long-expected attack occurs, the narrator reports that

Snowball, who had studied an old book of Julius Caesar's campaigns which he had found in the farmhouse, was in charge of the defensive operations. He gave his orders quickly, and in a couple of minutes every animal was at his post.

• Snowball orders the first attack.
• Snowball actually exposes himself to real danger by personally taking the lead in a second attack by the animals upon the humans.
• Snowball gives the signal for a strategic retreat, which he had obviously planned beforehand.
• Once the strategic retreat has been successful, Snowball himself heroically leads the counter-attack:

Snowball now gave the signal for the charge. He himself dashed straight for Jones. Jones saw him coming, raised his gun and fired. The pellets scored bloody streaks along Snowball's back, and a sheep dropped dead. Without halting for an instant, Snowball flung his fifteen stone [that is, his heavy weight] against Jones's legs. Jones was hurled into a pile of dung and his gun flew out of his hands.

Snowball, then, is wounded in the battle, and it is he himself who defeats the main enemy.

• When Boxer regrets having apparently killed a boy during the battle, it is Snowball who stokes his resolve:

'No sentimentality, comrade!' cried Snowball from whose wounds the blood was still dripping. ‘War is war. The only good human being is a dead one.'

Snowball can speak with such conviction and authority because he has obviously himself suffered in the battle (unlike Napoleon, modeled on Joseph Stalin, who is nowhere to be seen).

• When an animal killed in the conflict has to be buried, it is Snowball who pays her proper respects during her burial. Likewise, it is Snowball who draws the broader lesson from this event:

At the graveside Snowball made a little speech, emphasising the need for all animals to be ready to die for Animal Farm if need be.

In short, Snowball’s contributions to the battle are genuinely heroic and worthy of respect – a fact that makes his later expulsion from animal farm, and the denial of his heroism, seem all the more ironic.

In the Battle of the Cowshed, Snowball leads the animals to victory over the humans.  He is able to do this because he has read the works of Julius Caesar.  Later on, though, he is run off the farm and Napoleon claims that Snowball actually tried to help the humans in this battle.

The historical parallel for this is the experience of Leon Trotsky.  Trotsky was the military mastermind of the Communist forces in their revolution.  Later on, though, he was forced into exile by Stalin (Napoleon) and was eventually assassinated.

Snowball is declared a Hero First Class after the Battle of Cowshed.  He distinguishes himself in this battle that is a confrontation between the returning Farmer Jones and other farmers, armed with guns and sticks, who intend to take the farm back.

"Leon Trotsky was the military genius who built the Soviet Army and planned the military campaigns that gave victory to the Communists in the civil war that followed the Revolution. He is personified in Snowball, the first-class hero of the Battle of the Cowshed."

"With the Battle of the Cowshed, Orwell has combined several events from the closing years of World War I and years immediately after the Russian Revolution."

Snowball is fearless in his assault on the humans. He spent time studying the military campaings of Julius Ceasar, therefore he is knowledgeable on battle strategy.

During the Battle of Cowshed, Snowball launched the first attack. His strategy included a second wave attack which was designed to really assault the humans and force them to flee the farm again.

Snowball launched the second line of attack, along with Benjamin, Muriel and the sheep, they rushed forward and prodded and butted the men from every side." (Orwell)