He was the only person convicted of the bombing of Pan Am Flight 103 over Lockerbie.
To the end, Abdelbaset al Megrahi always insisted he was an innocent man and had nothing to do with the attack, which killed 270 people, most of them American students flying home for Christmas.
Born in Tripoli in 1952 and educated in the United States and the UK, the former Libyan intelligence officer was added to the FBI's 10 most wanted fugitives list seven years after the atrocity.
He did not fit the stereotype of an international terrorist.
Smartly dressed and quietly spoken, he portrayed himself as a family man who had been the victim of a terrible miscarriage of justice.
A director of Libya's Centre for Strategic Studies and later put in charge of Libyan
Arab Airlines' security operations, prosecutors said he used his position to organise, prepare and carry out the Lockerbie bombing .
Fragments of clothing, found wrapped around the timing device, linked him to the attack.
He was also identified by Maltese businessman Anthony Gauci, who claimed he sold
items of clothing and an umbrella to a Libyan man who looked "a lot" like Megrahi three weeks before the bombing.
After a lengthy investigation by UK and US police forces, Megrahi was indicted in 1991.
However, years of lengthy diplomatic bargaining with Libyan leader Colonel Muammar Gaddafi followed before he was handed over for trial.
Megrahi and his co-accused, compatriot Al Amin Khalifa Fhimah, eventually faced a trial in 2000, conducted under Scottish law at a specially convened court at Camp Zeist in the Netherlands.
Costing an estimated £75m, it was one of the most complex trials ever staged.
After almost seven months and evidence from 230 witnesses, Megrahi was eventually found guilty and sentenced to 27 years.
His co-accused was cleared.
A first appeal against his conviction was rejected in March 2002.
Five years later, his lawyers successfully applied to the Scottish Criminal Cases Review Commission and the case was referred back to the Court of Appeal.
Eight years after he was found guilty of blowing up the jet, Megrahi dropped the appeal.
On August 21, 2009, Megrahi was released from Greenock Prison on compassionate grounds amid a storm of protest from victims' families.
But while many of the relatives are convinced of his guilt, there are some, particularly in Britain, who believe he was innocent.
"I am an innocent man," he said in his last interview, in December 2011.
"I am about to die and I ask now to be left in peace with my family."
The death of the 60-year-old is unlikely to bring an immediate end to the legal and political controversy, as families of victims say many questions remain unanswered and calls for an inquiry into his early release continue.