Liberation Army of the South in the context of "Victoriano Huerta"

The Mexican Revolution (Spanish: Revolución mexicana) was an extended sequence of armed regional conflicts in Mexico from 20 November 1910 to 1 December 1920. It has been called "the defining event of modern Mexican history". It saw the destruction of the Federal Army, its replacement by a revolutionary army, and the transformation of Mexican culture and government. The northern Constitutionalist faction prevailed on the battlefield and drafted the present-day Constitution of Mexico, which aimed to create a strong central government. Revolutionary generals held power from 1920 to 1940. The revolutionary conflict was primarily a civil war, but foreign powers, having important economic and strategic interests in Mexico, figured in the outcome of Mexico's power struggles; the U.S. involvement was particularly high. The conflict led to the deaths of around one million people, mostly non-combatants.

Although the decades-long regime of President Porfirio Díaz (1876–1911) was increasingly unpopular, there was no foreboding in 1910 that a revolution was about to break out. The aging Díaz failed to find a controlled solution to presidential succession, resulting in a power struggle among competing elites and the middle classes, which occurred during a period of intense labor unrest, exemplified by the Cananea and Río Blanco strikes. When wealthy northern landowner Francisco I. Madero challenged Díaz in the 1910 presidential election and Díaz jailed him, Madero called for an armed uprising against Díaz in the Plan of San Luis Potosí. Rebellions broke out first in Morelos (immediately south of the nation's capital city) and then to a much greater extent in northern Mexico. The Federal Army could not suppress the widespread uprisings, showing the military's weakness and encouraging the rebels. Díaz resigned in May 1911 and went into exile, an interim government was installed until elections could be held, the Federal Army was retained, and revolutionary forces demobilized. The first phase of the Revolution was relatively bloodless and short-lived.

The Constitutional Army (Spanish: Ejército constitucional), also known as the Constitutionalist Army (Spanish: Ejército constitucionalista), was the army that fought against the Federal Army, and later, against the Villistas and Zapatistas during the Mexican Revolution. It was formed in March 1913 by Venustiano Carranza, so-called "First-Chief" of the army, as a response to the murder of President Francisco I. Madero and Vice President José María Pino Suárez by Victoriano Huerta during La Decena Trágica (Ten Tragic Days) of 1913, and the resulting usurpation of presidential power by Huerta.

Carranza had a few military forces on which he could rely for loyalty. He had the theoretical support of Pancho Villa and Emiliano Zapata, but they soon turned against the Constitutionalists after Huerta's defeat in 1914.

Emiliano Zapata Salazar (Latin American Spanish: [emiˈljano saˈpata]; 8 August 1879 – 10 April 1919) was a Mexican revolutionary and guerrilla leader. He was a leading figure in the Mexican Revolution of 1910–1920, the main leader of the people's revolution in the Mexican state of Morelos, and the inspiration of the agrarian movement called Zapatismo.

Zapata was born in the rural village of Anenecuilco, Morelos in an era when peasant communities came under increasing repression from the small-landowning class who monopolized land and water resources for sugarcane production with the support of dictator Porfirio Díaz (President from 1877 to 1880 and 1884 to 1911). Zapata early on participated in political movements against Díaz and the landowning hacendados, and when the Revolution broke out in 1910 he became a leader of the peasant revolt in Morelos. Cooperating with a number of other peasant leaders, he formed the Liberation Army of the South, of which he soon became the undisputed leader. Zapata's forces contributed to the fall of Díaz, defeating the Federal Army in the Battle of Cuautla in May 1911, but when the revolutionary leader Francisco I. Madero became president he disavowed the role of the Zapatistas, denouncing them as mere bandits.

Gildardo Magaña Cerda (March 7, 1891 – December 13, 1939) was a Mexican general, politician and revolutionary.

Born on March 7, 1891, in Zamora, Michoacán to a Liberal trading family, Magaña was sent to study economics in the United States at the Temple College in Pennsylvania. Back in Mexico he was involved in the anti-reelectionist movement and had to flee to the insurrectionist Zapatista country people in Morelos in 1911. He was immediately made use of as emissary to various revolutionaries in different parts of Mexico, among others to Pancho Villa whom he is reported to have taught reading. In 1916 he was appointed chief of staff to Emiliano Zapata, because he was the only one who was able to make unruly sub-commanders of the movement cooperate instead of quarrel, using his personal charm as well as his outstanding diplomatic skill for the task.