Mexico The United Mexican States, more commonly referred to only as Mexico, is a federal republic that became independent from Spanish rule in 1821. The areas that comprise present-day Mexico were conquered by the Spanish in the early 16th century when the dominant Aztec empire was destroyed by the invaders. About 300 years of colonial rule within the New Spain colony followed, during which many Spanish migrated to the new continent. Mexico declared its independence in 1810 and fought Spain to achieve this end until 1821, when the country was recognised as independent. Mexico first became an empire under Emperor Ituribe, but this model of governance was replaced by a republican constitution already in 1824.

As in many other Latin American countries that had been under Spanish colonial rule Mexico's post-independence politics, up until modern times, became dominated by the rivalry of the Liberals and the Conservatives. Between independence and the early 20th century this divide left its mark on the country through mostly unconstitutional rule and dictatorships, coupled with economic inequality, characterising the federation. The better part of the 20th century saw the country being controlled by the PRI (Institutional Revolutionary Party), which dominated elections (at times through oppression and manipulation) for 70 years before being defeated in the 2000 elections by the PAN (National Action Party). By then Mexico had made substantial progress in the democratic and economic spheres.

Authoritarian politics and the economic marginalisation of some of Mexico's indigenous populations, primarily in the southern parts of the country, spawned widespread discontent among the poor and landless throughout the second half of the 20th century. This discontent sometimes took violent expressions, such as in the intrastate armed conflicts in the Chiapas state fought between the government and the EZLN (Ejército Zapatista de Liberación Nacional, Zapatista National Liberation Army) in 1994 and between the government and the EPR (Ejercito Popular Revolucionario, People's Revolutionary Army) in 1996. The conflict with the EZLN ended with a minimal accord on increased rights for the indigenous population; an accord that was not implemented to the satisfaction of the rebels. The conflict with the EPR was terminated by low activity.

In the context of the conflicts in Chiapas paramilitary groups supporting the government, such as the Paz y Justicia (Peace and Justice) group, made use of one-sided violence. Such violence mainly targeted Zapatista sympathisers.

Mexico has also experienced non-state conflict, primarily in the form of powerful criminal cartels fighting each other for dominance. Since 2006, the Mexican Government has aggressively targeted Mexican drug cartels using both civilian and military forces. The period between 2006 and 2011 saw a dramatic surge in the levels of non-state conflict, primarily in the form of powerful criminal cartels fighting each other for dominance of drug trafficking routes to the United States.

Since 1946 Mexico has experienced the intrastate, non-state and one-sided categories of UCDP organised violence.