With one of the longest-running conflicts in the Western Hemisphere, the Colombian state has been facing an internal armed conflict against the FARC since the 1950s. Four milestones set the framework for the most important background in this conflict. The first one, with the murder of leader Jorge Eliecer Gaitan, unleashed acts of severe violence between liberals and conservatives; then, the second milestone was due to the creation of the “national front” that ended the disputes by rotating power between these political parties; however, other minority groups were not taken into account, giving rise to the third milestone, where the FARC guerrillas emerged by claiming a communist model, and the fourth milestone corresponds to heavy military strikes against this guerrilla group that forced the FARC to a negotiate peace accord. Considering the theory of escalation and stagnation of the armed conflict, this article aims at summarizing the background that has led to this conflict, which had its beginnings in political disputes but gradually escalated to become a serious problem that the country has been suffering.