At the age of 16 he moved to Villarrica, Tolima in 1953 where, during the dictatorship of General Gustavo Rojas Pinilla, joined the Alfonso Castañeda guerrilla group.
After numerous firefights with the Colombian Army his guerrilla group was forced to retreat to El Guayabero jungle, there he met guerrilla leader Dúmar Aljure and became commander, dubbed as "Comandante Nariño".