Conservative Party (Mexico) in the context of Mariano Paredes (President of Mexico)

The second French intervention in Mexico (Spanish: segunda intervención francesa en México), also known as the Second Franco-Mexican War (1861–1867), was a military invasion of the Republic of Mexico by the French Empire of Napoleon III, purportedly to force the collection of Mexican debts in conjunction with Great Britain and Spain. Mexican conservatives supported the invasion, since they had been defeated by the liberal government of Benito Juárez in a three-year civil war. Defeated on the battlefield, conservatives sought the aid of France to effect regime change and establish a monarchy in Mexico, a plan that meshed with Napoleon III's plans to re-establish the presence of the French Empire in the Americas. Although the French invasion displaced Juárez's Republican government from the Mexican capital and the monarchy of Archduke Maximilian was established, the Second Mexican Empire collapsed within a few years. Material aid from the United States, whose four-year civil war ended in 1865, invigorated the Republican fight against the regime of Maximilian, and the 1866 decision of Napoleon III to withdraw military support for Maximilian's regime accelerated the monarchy's collapse.

The intervention came as a civil war, the Reform War, had just concluded, and the intervention allowed the Conservative opposition against the liberal social and economic reforms of President Juárez to take up their cause once again. The Catholic Church, conservatives, much of the upper-class and Mexican nobility, and some indigenous communities invited, welcomed and collaborated with the French empire to install Maximilian as Emperor of Mexico. However, there was still significant support for republicanism in Mexico. Mexican society was most resistant to European models of governance, including monarchies, during and after the French intervention. The emperor himself however proved to be of liberal inclination and continued some of the Juárez government's most notable measures. Some liberal generals defected to the empire, including the powerful, northern governor Santiago Vidaurri, who had fought on the side of Juárez during the Reform War.

Maximilian I (Spanish: Fernando Maximiliano José María de Habsburgo-Lorena; German: Ferdinand Maximilian Josef Maria von Habsburg-Lothringen; 6 July 1832 – 19 June 1867) was an Austrian archduke who became emperor of the Second Mexican Empire from 10 April 1864 until his execution by the Mexican Republic on 19 June 1867.

A member of the House of Habsburg-Lorraine, Maximilian was the younger brother of Emperor Franz Joseph I of Austria. Before becoming Emperor of Mexico, he was commander-in-chief of the small Imperial Austrian Navy and briefly the Austrian viceroy of Lombardy–Venetia, but was removed by the emperor. Two years before his dismissal, he briefly met with French emperor Napoleon III in Paris, where he was approached by conservative Mexican monarchists seeking a European royal to rule Mexico. Initially Maximilian was not interested, but following his dismissal as viceroy, the Mexican monarchists' plan was far more appealing to him.

José de la Cruz Porfirio Díaz Mori (/ˈdiːəs/; Spanish: [poɾˈfiɾjo ˈði.as]; 15 September 1830 – 2 July 1915) was a Mexican general and politician who was the dictator of Mexico from 1876 until his overthrow in 1911, seizing power in a military coup. He served on three separate occasions as President of Mexico, a total of over 30 years, this period is known as the Porfiriato and has been called a de facto dictatorship. Díaz’s time in office is the longest of any Mexican ruler.

Díaz was born to a Oaxacan family of modest means. He initially studied to become a priest but eventually switched his studies to law, and among his mentors was the future President of Mexico, Benito Juárez. Díaz increasingly became active in Liberal Party politics fighting with the Liberals to overthrow Santa Anna in the Plan of Ayutla, and also fighting on their side against the Conservative Party in the Reform War.

The Second Federal Republic of Mexico (Spanish: Segunda República Federal de México) refers to the period of Mexican history involving a second attempt to establish a federal government in Mexico after the fall of the unitary Centralist Republic of Mexico in 1846 at the start of the Mexican-American War. It would last up until the Second French Intervention in Mexico led to the proclamation of the Second Mexican Empire in 1863.

The period of the Second Federal Republic prove to be one of the most eventful periods in Mexican history, experiencing two foreign invasions, the loss of half of the national territory, constitutional change, and a civil war. It was also a period of Mexican political evolution experiencing the downfall of the Conservative Party that had predominated during the Centralist Republic, and marking the rise of a Liberal Party hegemony which would consolidate itself throughout the rest of the century.

Ignacio Gregorio Comonfort de los Ríos (Spanish pronunciation: [iɣˈnasjo komoɱˈfoɾ ðe los ˈri.os]; 12 March 1812 – 13 November 1863), also known as Ignacio Comonfort, was a Mexican politician and soldier who was also president during La Reforma.

He played a leading role in the liberal movement under the Plan of Ayutla to overthrow the dictatorship of Santa Anna in 1855; he then served in the cabinet of the new president, Juan Álvarez. Comonfort was a moderate liberal and assumed the presidency when Álvarez stepped down after only a few months. The Constitution of 1857 was drafted during his presidency, incorporating changes enacted in individual laws of the Liberal Reform. The constitution was met with opposition from conservatives as its forceful anticlerical provisions undermined the economic power and privileged status of the Catholic Church as an institution. Most notably the Lerdo law stripped the Church's ability to hold property. The law also forced the breakup of communal land holdings of indigenous communities, which enabled them to resist integration economically and culturally. The controversy was further inflamed when the government mandated that all civil servants take an oath to uphold the new constitution, which left Catholic public servants with the choice between either keeping their jobs or being excommunicated.

The Liberal Party (Spanish: Partido Liberal, PL) was a loosely organised political party in Mexico from 1822 to 1911. Strongly influenced by French Revolutionary thought, and the republican institutions of the United States, it championed the principles of 19th-century liberalism, and promoted republicanism, federalism, and anti-clericalism. They were opposed by, and fought several civil wars against, the Conservative Party.

Cinco de Mayo (Mexican Spanish: [ˈsiŋko ðe ˈmaʝo]; Spanish for 'Fifth of May') is an annual celebration held on May 5 to celebrate Mexico's victory over the Second French Empire at the Battle of Puebla in 1862, led by General Ignacio Zaragoza. Zaragoza died months after the battle from an illness, however, and a larger French force ultimately defeated the Mexican army at the Second Battle of Puebla and then occupied Mexico City. Following the end of the American Civil War in 1865, the United States began lending money and guns to the Mexican Liberals, pushing France and Mexican Conservatives to the edge of defeat. At the opening of the French chambers in January 1866, Napoleon III announced that he would withdraw French troops from Mexico. In reply to a French request for American neutrality, the American secretary of state William H. Seward replied that French withdrawal from Mexico should be unconditional.

More popular in the United States than in Mexico, Cinco de Mayo has become associated with the celebration of Mexican-American culture. Celebrations began in Columbia, California, where they have been observed annually since 1862. The day gained nationwide popularity beyond those of Mexican-American heritage in the 1980s due to advertising campaigns by beer, wine, and tequila companies; today, Cinco de Mayo generates beer sales on par with the Super Bowl. In Mexico, the commemoration of the battle continues to be mostly ceremonial, such as through military parades or battle reenactments. The city of Puebla marks the event with various festivals and reenactments of the battle.