1990 - Liberian civil war
Rebel leader Charles Taylor - who is now Liberia's president - launched a revolt against the government close to the Guinea border in December 1989.
In the civil war that followed, 500,000 refugees flooded across the border, mainly to Guinea, but also to Ivory Coast.
Guinea, along with other West African countries, formed an intervention force to stop Charles Taylor.
They were helped by some of the more politically active Liberian refugees, who eventually formed the rebel movement Ulimo-K.