Battle for the Planet of the Apes

Aldo murdered Cornelius because the young ape accidentally overheard Aldo plotting his coup against Caesar. When Cornelius clung to a tree branch to listen, Aldo sliced the branch with his sword, causing Cornelius to fall to his death. This eliminated a potential witness to Aldo's treason while also serving as a warning to anyone who might oppose his plans.

Aldo's ambition and opposition to peace with humans had been established earlier when he urged imprisoning human laborers and attacked teacher Abe.

After the apes counterattacked and captured most of Governor Kolp's forces, Caesar refused Aldo's demand to execute them. He chose mercy over vengeance, recognizing that apes could become as brutal as the humans they once opposed. This decision reflected Caesar's belief that peace between species was still possible despite the conflict.

Caesar had spent the entire film working toward coexistence, rejecting the violence advocated by Aldo.

Caesar journeyed to the Forbidden City after his assistant MacDonald discovered archived footage showing the radiation-ravaged remnants of the city and the oppressed humans living under Governor Kolp's rule. The footage also contained recordings from Caesar's parents, Cornelius and Zira, warning about humanity's destructive potential. Caesar went to investigate the threat these mutant humans posed to Ape City.

The footage revealed that Kolp's forces were preparing to attack Ape City, directly triggering the film's final conflict.

The war began when Caesar, MacDonald, and Virgil discovered that Governor Kolp's mutant humans were planning an assault on Ape City. This revelation came from the footage showing Kolp's forces preparing for battle. Additionally, Caesar's presence in the Forbidden City and his escape from Kolp's soldiers convinced the governor that apes were coming to attack him, prompting his preemptive strike.

Caesar's warning to the apes about Kolp's intentions was dismissed, allowing the conflict to escalate.

Aldo believed apes should dominate humans, not coexist with them. As a gorilla general, he represented the militaristic faction that viewed human survival as unnecessary. He actively worked to undermine Caesar's diplomatic efforts by inciting violence against humans and eventually staging a coup to seize power. His philosophy directly contradicted Caesar's vision of interspecies harmony.

Aldo's hostility was first shown when his followers attacked human teacher Abe for teaching apes.

The apes defeated Kolp's army by feigning defeat and retreating, which deceived the mutant humans into thinking they had won. Once Kolp's forces entered Ape City believing they had succeeded, the apes launched a major counteroffensive and captured most of the attacking force. This strategy turned the tide of the war in the apes' favor.

Caesar ordered a strategic retreat during the initial assault, setting up the deceptive counterattack.

After defeating Kolp's forces and killing Aldo, Caesar decided to lock the weapons away rather than keep them ready for future conflicts. He acted on his friend MacDonald's appeal to treat humans humanely. This symbolized Caesar's commitment to peace and his refusal to let apes become like their former human oppressors, choosing hope over perpetual warfare.

This decision directly followed Caesar's realization that apes could mirror the brutality of humans.

The footage, found by MacDonald in the Forbidden City, showed Caesar's parents Cornelius and Zira among the irradiated ruins. It contained their warnings about the catastrophic destiny awaiting Earth due to nuclear war. These recordings served as a haunting reminder of the past and reinforced the urgency of preventing further destruction.

The footage foreshadowed the ongoing consequences of nuclear conflict that still defined the world in 2670.

According to the epilogue narrated by the Lawgiver, Caesar died sometime after the conflict with Kolp's forces. Over 600 years later, his legacy endured as a symbol of hope for peaceful coexistence between apes and humans. A statue of Caesar was shown with a single tear falling from its eye, representing the lasting impact of his leadership and his dream of a world without weapons.

The film opened with the Lawgiver setting up this reflection on Caesar's legacy.

Governor Kolp launched the attack on Ape City after Caesar, MacDonald, and Virgil escaped from the Forbidden City. Kolp feared that Caesar had come to destroy him and his regime, interpreting the ape's presence as a declaration of war. This paranoia, combined with his desire to eliminate the apes before they could threaten his power, drove him to unleash his forces against Ape City.

Caesar's escape from Kolp's soldiers was witnessed by the governor himself, confirming his suspicions.

The sacred ape law stated "ape shall never kill ape." This principle was central to ape society and represented their attempt to rise above human violence. When Aldo murdered Cornelius, he violated this fundamental law, which was why the other apes reacted with such outrage when Virgil revealed Aldo's crime. The betrayal of their own kind was considered the ultimate transgression.

The law had been referenced throughout the film as a cornerstone of ape civilization.