Few can justly claim to be legends in their own lifetime. But Viktor Bout has earned that label and many others besides. For at least two decades he was the go-to black market arms dealer, "Merchant of Death" and "personification of evil". His empire inspired a slew of authors and even a Hollywood movie. All that will come to an end in a New York courtroom this week, most likely with a jail sentence lasting as long as he was in business.

Viktor Anatolyevich Bout – aka Viktor But, Butt, Budd, Bulakin and Vadim Markovich Aminov – is, according to US federal prosecutors, the mastermind behind the world's largest illegal international arms-trafficking network. Those same prosecutors have demanded a 25-year mandatory life sentence for a man they describe as a "businessman of the most dangerous order" who was "ready, willing and able to provide a breathtaking arsenal of weapons" to terrorists.

Bout, 45, born in Tajikistan, will appear for sentencing on Thursday. He has already been found guilty of conspiring to kill US citizens and aiding terrorists. The prosecution has also asked judge Shira Scheindlin to order him to forfeit $20m.

According to experts, Bout's network has fuelled wars and conflict throughout Africa, the Balkans and the Middle East resulting in the slaughter of millions of people. He is accused of selling munitions to the Taliban and al-Qa'ida which were then used to target British and American troops.

One US Secretary of State described Bout as the "personification of evil": he was unmoved. The thinly disguised 2005 Hollywood biopic Lord of War, starring Nicolas Cage, left him similarly unimpressed. "I feel sorry for Nicolas Cage," he said. "It's a bad movie."

Inevitably, his arrest in Thailand in 2008, after decades of eluding the authorities, provided a drama worthy of another Hollywood film. He was captured in a Bangkok hotel after undercover US Drug Enforcement Administration (DEA) agents lured him from Moscow in a sting operation run across three continents. Posing as members of Farc, the Colombian terrorist group, the DEA agents convinced Bout they wanted to buy millions of dollars worth of weapons from him to use to shoot down US helicopter pilots and kill US citizens.

After his arrest, Bout, backed by the Russian government, publicly fought extradition to the US for two years before finally being sent. He was found guilty last November.

A British-born businessman, Andrew Smulian, arrested with Bout in Thailand, became a key witness for the prosecution and will also be sentenced on Thursday. Cambridge-born Smulian, 70, was described in court papers as a long-time business associate of Bout and served as an adviser to one of his airlines. In November 2007, Smulian was contacted by a DEA informant who told him he had a deal for Bout. During a series of meetings around the world – including Denmark, Romania and Curaçao in the Caribbean – the informant claimed Farc wanted Bout to supply $15m worth of weapons including more than 100 ground-to-air missiles to attack US helicopters.

Smulian, who pleaded guilty and became a co-operating witness, gave evidence in court protected by US marshals, admitting that he hoped to earn a reduction in his own sentence. Smulian said he first met Bout in South Africa in the 1990s when he found an airfield for the Russian's cargo planes. Bout, he said, introduced him to Mikhail Kalashnikov, the inventor of the AK-47 assault rifle, at an arms fair in the Middle East.

It was during this time that the "Merchant of Death" was first identified by the United Nations as a key violator of arms embargoes imposed to stop bloodshed in Africa. A UN report accused him of supplying arms and equipment into Liberia, Angola and several other countries racked by conflict.

Bout's gun-running activities prompted the then Foreign Office minister Peter Hain to coin the name the "merchant of death", describing him as "the principal conduit for planes and supply routes that take arms... from East Europe, principally Bulgaria, Moldova and Ukraine, to Liberia and Angola". In 2003, Mr Hain said: "The UN has exposed Bout as the centre of a spider's web of shady arms dealers, diamond brokers and other operatives sustaining the wars."

Analysis of Bout's laptop, seized when he was arrested, contained evidence that the Russian had set up hundreds of shell companies around the globe for his air cargo and other business ventures, stretching from small Pacific islands to the US.

A former translator for the Russian military and officer in the Soviet air force, Bout is said to have close links with Russian intelligence. His father-in-law "at one point held a high position in the KGB, perhaps even as high as a deputy chairman", according to a 2002 UN report.

His trial was closely monitored by the Russian government who strongly opposed his extradition to the US. The Duma, the Russian parliament, warned that US-Russian relations could be affected by the outcome of the trial.

Bout's lawyer in the US, Albert Dayan, claims the case against his client was "the product of outrageous, inexcusable government conduct" and that his client was innocent.