50 000 Pesos Mariano Ospina Perez

Ospina Pérez served as Colombian president from 1946 to 1950, a period that included the April 1948 assassination of Jorge Eliécer Gaitán in Bogotá — the spark that ignited La Violencia, a civil conflict that ultimately killed an estimated 200,000 Colombians over the following decade. His administration's handling of that crisis remains one of the most contested chapters in Colombian political history.

The 1991 issue date places this coin at a pivotal constitutional moment: Colombia was in the process of replacing its 1886 constitution, with the new charter adopted that same July.