Mexican revolutionary Emiliano Zapata leads the peasants against a corrupt president.

In 1909, a delegation of Indians from the Mexican state of Morelos travel to Mexico City to plead for the return of land stolen from them. They are received by president Porfirio Díaz, who has ruled as dictator for thirty-four years, and his preferential treatment of landowners is revealed by his condescending attitude toward the peasants. One of the men, Emiliano Zapata, insists that Díaz give them authority to enforce their rights, and Díaz circles Zapata's name on the petition so that he can be watched in the future. Back in Morales, when the Indians attempt to survey their stolen land, soldiers set up a machine gun and a massacre begins. Zapata leads the fight against the soldiers, and his actions make him a wanted criminal. While Zapata hides in the mountains with his brother Eufemio, friend Pablo and follower Soldadera, news of his stand against Díaz' corruption spreads, and he is visited by journalist and political zealot Fernando Aguirre. Fernando suggests that Zapata join the cause of Francisco Indalecio Madero, an exiled Mexican leader attempting to overthrow Díaz, but Zapata, reluctant to trust someone he does not know, sends Pablo to meet him. Zapata then goes with Eufemio to a nearby town, where he meets with his sweetheart Josefa, whose storeowner father, Señor Espejo, refuses to allow her to marry the outlaw. Hoping to become respectable, Zapata, renowned for his knowledge of horses, accepts a job with Don Nacio de la Torre, who succeeds in obtaining a pardon for him. When Pablo and Fernando return from meeting with Madero, they urge Zapata to join him, but Zapata, hoping for a peaceful life with Josefa, refuses. Before Zapata can win Josefa's hand, however, he is outraged by the Federales' cruel treatment of an old Indian man, and kills the soldiers. Espejo again forbids Zapata to marry his daughter, but Zapata's popularity with the people is solidified when they prevent the police from arresting him. As the weeks pass, Zapata and his followers engage in battles with Díaz' soldiers, and one day, Zapata rewards a brave youngster with his own treasured white horse. When Madera names Zapata his general in the south, as Pancho Villa is his general in the north, Espejo allows Zapata to court Josefa. After Díaz flees Mexico and Madera assumes control of the government, Josefa and Zapata marry, and on their wedding night, Josefa begins to teach her husband how to read. Soon after, Zapata visits Madera in Mexico City and is infuriated when the well-meaning but naive Madera offers him a rich estate as reward for his support, then declares that the reinstatement of the Indians' land will take time. Fernando cynically states that although Madera is honest, he is controlled by the same men surrounding Díaz, but Zapata decides to give Madera time to prove himself. Corrupt general Huerta urges Madera to kill Zapata, who he thinks is too powerful, although Pablo persuades Madera to visit Zapata in Morales and see him with the people. Madera attends a celebration in Zapata's village, where the men turn in their weapons, but the fiesta ends when Huerta sends his army in to kill Zapata. Forced again to fight, Zapata engages in many battles with Huerta's forces, while Madera is held captive and then assassinated. Soon after, an ambush on Zapata's forces leads him to suspect that a traitor has betrayed him, and when he learns that Pablo had been communicating with Madera, he executes his old friend himself. Huerta is soon defeated, and Villa and Zapata meet with other revolutionary leaders in Mexico City, where it is decided that the weary Zapata will become the president. Later, a delegation from Morales visits Zapata to inform him that Eufemio has turned into a despot, stealing land and other men's wives. Infuriated when he finds himself circling the leader's name on the petition, Zapata resigns and returns home to confront Eufemio. Eufemio defends his actions, remarking that Zapata has remained poor, then is killed by the husband of a woman he has seduced. Sick of politics, Zapata returns to his army, and the new president, spurred on by Fernando, decides that in order to consolidate his power, Zapata must be killed. Using a cache of ammunition as bait, a trap is laid, and although Josefa urges Zapata not to go, he travels to the fort where the ammunition is supposedly held. There, Col. Jesús Guajardo reunites Zapata with his beloved white horse before he is shot by dozens of soldiers. After the horse escapes, Zapata's mutilated body is displayed in a nearby village courtyard. The people refuse to accept that the corpse is Zapata's, however, and believe that his horse, running free in the mountains, is a sign that he will return when he is needed.