Moroccan revolutionary politician exiled to Paris whose abduction and presumed murder in October 1965 caused a political crisis for the government of French President Charles de Gaulle and led to ruptured diplomatic relations between France and Morocco for almost four years.

Ben Barka, the son of a Moroccan policeman, taught mathematics before he entered political life. He joined the Istiqlal Party, becoming speaker of the National Consultative Assembly, and in 1959 left the party to found the left-wing National Union of Popular Forces (UNFP). He was widely considered as a likely president for a possible Republic of Morocco. When Morocco and Algeria had a brief war in 1963, Ben Barka sided with Algeria and went into exile. He was subsequently accused of high treason for an alleged plot against King Hassan II and was sentenced in absentia to death. He moved to Paris and became leader-in-exile of the opposition to Hassan.

On Oct. 29, 1965, Ben Barka disappeared. He was never found, and investigators concluded that gangsters were paid to kidnap and murder him. It was suggested several times that the plot was headed by General Muhammad Oufkir, Hassan's minister of the interior. A formal inquiry and trial in France showed that Morocco had violated French national sovereignty and, worse yet, that French police officers and members of French intelligence had been involved in the affair. France issued an international warrant for Oufkir's arrest, which was ignored. Relations between the two countries deteriorated steadily over the incident until January 1966, when diplomatic relations were severed.