Colombia The northern region of South America constituted the Spanish colonial "New Granada" until an armed struggle forced the Spanish out in 1819. The newly created Union of Gran Colombia collapsed in 1830, establishing the states of Colombia (including Panama until 1903), Ecuador, and Venezuela.

Colombian political life became dominated by two parties; the conservatives and the liberals. Following the assassination of left-wing liberal party leader Jorge Eliécer Gaitán in 1948, riots erupted in Bogotá and violence soon spread across the country. The following decade, known as "La Violencia", was characterized by intense fighting between numerous non-state armed groups. These included local conservative party and liberal party organizations but also socialists, bandits, peasant organizations, and the private armies of large landowners. In 1958, the conservative and liberal parties agreed to a 16-year coalition government, thus excluding other political actors. In the mid-1960s, several left-wing groups such as FARC, ELN, EPL and M-19 started armed struggles against the government. During the conflict, both insurgent and government forces have targeted civilians whom they claim support the other side.

The guerrillas grew in strength due to profitable kidnappings and taxation of the growing illegal drug trade from Colombia. In the early 1980s, several paramilitary groups were formed by large landowners and drug lords for protections against guerrillas, a development supported by many local politicians and members of the military. These private armies did not limit their activity to fighting the guerrillas, but were also responsible for one-sided violence and other human rights violations. There were also attempts to influence government policy through attacks on government employees or civilian targets, especially in connection to threats of extraditing drug lords to the USA. The paramilitary groups originated as small local armed gangs, but most eventually joined the nation-wide organization AUC.

Colombian troops supported South Korea in the interstate conflict against North Korea during 1951-53.

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