Bout, who was arrested on Thursday in Bangkok following a United States sting operation in Bangkok, spoke six languages and has been linked to civil wars in Africa, the Taleban militia, Al-Qaeda and Marxist rebels in South America.
His notorious career inspired a Hollywood film - the Nicholas Cage vehicle 'Lord of War' - and the moustachioed former pilot has become a target for arms control pressure groups and law enforcement agencies from several countries.
Bout was born in the Tajikistan capital Dushanbe in 1967 and studied several languages - including English, French and Portuguese - at Moscow's military institute for foreign languages before joining the Soviet air force.
He has repeatedly denied suggestions that he was a former member of the KGB, but in a 2003 interview with the New York Times he admitted that in 1992 he bought three Antonov transport planes for US$120,000 (S$166,000).
The fall of the Soviet Union spelt a windfall for Bout, allowing him to buy Soviet-era weaponry, aircraft and helicopters at throwaway rates and supply them to fighters in some of the world's bloodiest conflict zones.
The planes and helicopters as well as the crew manning them were hardy, low maintainance and above all very cheap.
Former British foreign minister Peter Hain dubbed him the 'Merchant of Death' and rights watchdog Amnesty International has alleged that at one time he operated a fleet of more than 50 planes ferrying weapons around Africa.
The British press has also linked him to Al-Qaeda and to Afghanistan's extremist Taleban movement. Bout is also suspected of smuggling arms to former Liberian president Charles Taylor, who was subject to an United Nations arms embargo.
Journalist Douglas Farah, who co-authored a book on Bout, has called him 'a unique creature born of the end of Communism and the rise of unbridled capitalism when the Wall came down in the early 1990s'.
'He saw ... abandoned aircraft on the runways from Moscow to Kiev, no longer able to fly because of lack of money for fuel or maintenance; huge stores of surplus weapons that were guarded by guards suddenly receiving little or no salary; and the booming demand for those weapons from traditional Soviet clients and newly emerging armed groups from Africa to the Philippines.
'He simply wedded the three things, taking aircraft for almost nothing, filling them with cheaply purchased weapons from the arsenals, and flying them to clients who could pay,' Mr Farah said.
But his notoriety ultimately led to his arrest at a Bangkok luxury hotel in a sting operation by US agents posing as Colombian rebels.
'He became a celebrity in a sense because of NGOs and UN reporting about him,' said Mr Alex Vines, head of the Africa programme at Britain's Royal Institute of International Affairs.
'He became the brand name for sanction-busting, but there are plenty of others who can offer the same services. It contributed to his problems, that he was a brand to be recognised,' he said.
'This is a business that doesn't do well with this kind of recognition.' -- AFP