The last ended in 1958 when the Liberals and Conservatives set up the National Front in which they agreed to rotate power between them every four years, excluding other political parties and so giving birth to the insurgency and the current civil conflict that has raged for four decades.
Colombia's current troubles have their roots in what is called The Violence, a senseless, murderous civil conflict that raged from 1948 to 1958, killing more than 200, 000 people.