Abdul Quader Molla had carved out a reputation as a wily political strategist, before his past as the "Butcher of Mirpur" in Bangladesh's independence war came back to haunt him.
As one of the leaders of the country's largest Islamist party, Molla helped Jamaat-e-Islami forge an alliance with the Bangladesh Nationalist Party (BNP), which went on to win a landslide election victory a decade ago.
But to survivors of the 1971 war in which East Pakistan broke free from the regime in Islamabad, Molla's hands would be forever dripping with the blood of hundreds of civilians who died in the conflict.
Molla, who became Thursday the first Bangladeshi to be hanged for his role in the war, was dubbed the "Butcher of Mirpur" for overseeing the killing of some 350 civilians in a Dhaka suburb during the nine-month conflict.
Three hundred of the victims died in just one day, making it one of the most notorious episodes of a conflict that continues to divide Bangladesh more than four decades on.
During his trial before a much-criticised domestic tribunal, Molla insisted that he was a physics student at the Dhaka University and was innocent of all charges.
But he was found guilty after a woman who was just 13 years old at the time recounted before the court how he had been responsible for the killing of six members of her family.
Prosecutors said Molla had been a leading figure of the militia which carried out the killings, including of a well-known poet and a senior journalist.
Much of what was then East Pakistan's intelligentsia was killed in the final stages of the war in December 1971.
Allied to the regime in Islamabad, the militias were behind the massacre of dozens of professors, doctors and writers.
But despite their defeat, few of the militia leaders were ever brought to justice. Many instead became leading lights in Jamaat or joined the right-wing BNP.
A shy man with a deceptive smile, Molla was the chief ideologue of Jamaat and served as the executive editor of its mouthpiece, Dainik Sangram, for years before he was elevated to assistant secretary general, the fourth-highest position in the party's echelon.
The 65-year-old shot to prominence in the late 1990s when he played a key role in forging an enduring alliance between Jamaat and the BNP.
Together they won the 2001 elections by a landslide.
But he was arrested in 2010 after the secular Awami League party stormed back to power, pledging to probe the 1971 war crimes.
The opposition called the war crimes trials a sham, saying the government was conducting a witch-hunt of its opponents ahead of elections due to be held next month.
Molla was originally sentenced to a life term by the war crimes court in February.
But while he and his supporters said the outcome was a travesty, tens of thousands of secular activists took to the streets to denounce the sentence as too lenient.
Under pressure, the government amended the war crimes law retroactively, allowing it to appeal the sentence and seek the death penalty, which the Supreme Court then handed down in September.
Molla's wife and children were allowed a final meeting with him at the prison hours before Thursday's execution, and found him to be "calm".
"He told us that he is proud to be a martyr for the cause of the Islamic movement in the country," his son Hasan Jamil told AFP.