Juan Álvarez was born on 27 January 1790 at Santa María de la Concepción de Atoyac, now Atoyac de Álvarez, Guerrero. He was of peninsular Spanish and Afro-Mexican heritage. His father was an immigrant from Galicia in northwest Spain, where the pilgrimage site of Santiago de Compostela is located. His mother was Rafaela Hurtado, a parda (person of African descent), from Mexico’s Pacific Ocean port of Acapulco. Because of his Spanish roots, Álvarez would be known as “The Galician” during the Mexican Independence war. He studied in primary school in Mexico City, but returned to his native town at age 17 to receive his inheritance. He worked as a cowboy and in the fields. His father died in 1807 when Álvarez was seventeen. Further complicating his life was that his father’s land was tied up in a dispute over debts with a Spanish official. At the outbreak of the Mexican War of Independence in 1810, troops of insurgent priest José María Morelos came through Álvarez’s remote village of Atoyac, and he joined the insurgency.

In November 1810, at the age of 20, Alvarez joined the fight for Mexican independence as a private under the command of José María Morelos y Pavón. He fought in the battles of Aguacatillo, Tres Palos, Arroyo del Moledor, Tonaltepec and La Sabana, soon rising to the rank of captain. Before the year was out, he was wounded by a ball that pierced both legs, and he was given the command of the Guadalupe Regiment. In the assault on Tixtla on 15 May 1811, he was wounded again. He was now a colonel.

After the royalist defeat of the insurgents in central Mexico, guerrilla forces continued to fight against Spanish rule. Morelos was captured and executed in 1815, and Álvarez joined the forces of Afro-Mexican commander Vicente Guerrero. Royalist officer Agustín de Iturbide was called back into military service after a forced retirement for mishandling of funds. Iturbide suffered a series of defeats by insurgent forces, including those under Generala Antonia Nava de Catalán, one of the few women insurgent leaders. By 1820 when Spanish liberals seized control of the Spanish government, Iturbide was in contact with royalist high clergy, who began to speak of independence as a way to maintain their power, since Spanish liberals sought to curtail Church power. With the insurgency at a stalemate, the search was on to find a way out. Iturbide and Guerrero came into contact, with the two exchanging a series of letters to find a way forward. Iturbide began drafting a political plan, which initially did not include language guaranteeing equality of Afro-Mexicans in the post independence period. Guerrero strongly argued that they be included. A clause was part of the final draft of the Plan of Iguala read “All inhabitants of New Spain, without distinction to their being Europeans, Africans, or Indians, are citizens of this Monarchy with the option to seek all employment according to their merits and virtues.” Guerrero approved of the final draft and the alliance between the old insurgent and the royalist-turned-insurgent created political moment to achieve independence. However, there were members of the old insurgency, including Alvarez as well as Isidoro Montesdeoca, Pedro Asencio, and Gordiano Guzmán who objected to the Plan on a variety of grounds. These rejectionists continued to fight the royalists and agreed not to fight against Iturbide.

Under Iturbide’s revised Plan de Iguala, which insurgent guerrilla leader Vicente Guerrero had shaped to include demands of the Afro-Mexican insurgents, allied forces and formed the Army of the Three Guarantees. Álvarez was entrusted with taking key target of Acapulco from the royalists, which he did on 15 October 1821. He was named commander of Acapulco. From that point, he was one of the leaders of the insurgents and chief in the southern region. Alvarez deeply distrusted Iturbide and the American-born Spaniards who suddenly signed on to the struggle for independence. In a speech to his Afro-Mexican troops, Alvarez disparaged the character and motives of the creole elite. “We stand today as mortal enemies of all Creolismo … They have long tried to cover us with shame, to herd us as if we were four-legged beasts … to speak of us as if we were stupid animals, … and now they solicit our extermination … We say to the Creoles that we want our freedom.”

After independence, when Iturbide was proclaimed Emperor of Mexico in 1822, Álvarez joined with Guerrero and Anastasio Bustamante to fight against Iturbide’s monarchy.

Álvarez supported Guerrero during the latter’s presidency, fighting on his side in five battles. He was promoted to brigadier general in 1830. When Guerrero was overthrown by his vice-president, Bustamante, he joined Álvarez in the south, where they continued to resist. Álvarez tried to prevent Guerrero’s execution in 1831, but was unable to do so. IN the 1830s, he continued to oppose Bustamante’s centralism.

In 1838, Álvarez fought the French invaders in the Pastry War. In 1841, he was promoted to general of division. In 1845, he was given the military command of Oaxaca and the Department of Acapulco. In 1847, as general in chief of the cavalry he fought at the head of a division in the defense of the capital against the Americans in the Mexican–American War.

His stature and importance as a liberal leader with much regional power was one of the factors that led to the creation of the State of Guerrero in 1849. He was named its first (interim) governor, and after elections in 1850, he became its first constitutional governor. He served in that position until 1853.

On 1 March 1854 from Guerrero and seconded by Ignacio Comonfort, he proclaimed the Plan de Ayutla, a revolt against the dictatorship of Antonio López de Santa Anna. Álvarez joined the revolt against Santa Anna when the president showed indications he would intrude in Álvarez’s southern domain. Santa Anna was forced into exile in August 1855, and on 4 October 1855 in Cuernavaca, Morelos, Álvarez was installed as interim president of the Republic.

On 14 November 1855, Álvarez rode into Mexico City in the company of a bodyguard composed of regular militia, citizens and indigenous fighters from the south. His administration was short, but his cabinet was brilliantly staffed: Ignacio Comonfort was Minister of War; Melchor Ocampo was foreign minister; Guillermo Prieto was Minister of the Treasury; and Benito Juárez was Minister of Justice. In the 68 days that he governed, two measures were adopted that changed the destiny of Mexico: the convocation of a constituent congress that would write the Constitution of 1857, and the abolition of military and ecclesiastical fueros (privileges). The latter measure was the Ley Juárez (“Law of Juárez”).

Álvarez continued to take an interest in politics, faithful to his liberal republican principles. He took an active part in the War of the Reform, in support of Juárez. In 1861, Congress declared him Benemérito de la Patria.

During the French intervention that led to the arrival of Maximilian of Habsburg to claim the throne of the Second Mexican Empire, Álvarez, now an old man, was in command of the División del Sur. However, his son Diego was a high representative of the Empire in the Department of Acapulco. In 1862, President Juárez, who remained in the country with his government during the entire time of the Empire, ordered the republican military commanders in the east, south and southwest to take orders from Álvarez if communications were broken with Juárez. When Porfirio Díaz escaped from French captivity, he joined Álvarez in the mountains of Guerrero.

In 1867, Álvarez died on 21 August, a short time after the triumph of Mexican arms over the Empire, in his hacienda La Providencia, Guerrero, Mexico. On 25 December 1922, his remains were transferred with honors to the Rotonda de los Hombres Ilustres (Rotunda of Illustrious Men) in Mexico City.