Marco Antonio Yon Sosa (7 September 1929 – May 18, 1970) was the leader of the Revolutionary Movement 13th November, a Guatemalan guerrilla organization. Yon Sosa broke with the Stalinist Rebel Armed Forces in December 1964 over the question of a ceasefire, which he opposed.
He was affiliated to the Fourth International (Posadist)[1] from 1963 until 1966 when he was expelled from the International over accusing them of diverting funds which had been raised to support MR-13.[2] [3]
Yon was killed in a shootout with Mexican border police in 1970, in the Chiapas area near the Guatemalan border.
The circumstances of his death, however are disputed; Robert Lamberg notes in 1972 that Yon had been underground by that point for quite some time with the general circumstances making an armed confrontation with border forces unlikely.[4] Gino Perente notes that Yon Sosa hadn't died in some act of revolutionary heroism at all, but in a drunken car accident in downtown Guatemala City.[5]
Yon participated in the November 13, 1960, military uprising against president Miguel Ydígoras. Yon's father was a Chinese merchant,[6] and under his wing, MR-13 took on a decidedly Maoist orientation. He received part of his military training from the School of the Americas.[7]