In 1961, Peter Benenson read a newspaper report about two Portuguese students who had been arrested and jailed for drinking a toast to liberty in a cafe in Lisbon.
Mr Benenson died on Friday evening
Outraged, he decided to look at ways of highlighting the plight of all so-called "prisoners of conscience" around the world.
From that inspiration Mr Benenson, who died on Friday aged 83, founded Amnesty International.
Originally established as a one-year campaign, Amnesty is now the world's largest independent human rights organisation. Based in London, it has 1.8 million members and supporters worldwide.
Born on 31 July, 1921, Mr Benenson was tutored by WH Auden before going on to Eton and Oxford, where he studied history.
He joined the British Army after he graduated, where he worked for the Ministry of Information press office.
He took up a law practice after leaving the Armed Forces at the end of World War II.
He joined the Labour Party and the Society of Labour Lawyers and was sent to Spain by the TUC as an observer of the trials of trade unionists in the early 1950s.
Later in the decade he helped organise similar legal observer missions to South Africa and Hungary, but it was upon reading about the jailed Portuguese students that he was inspired to form a global grouping of human rights campaigners.
"It was during World Refugee Year ... which was set up to try to empty the displaced person camps all over Europe and it was a tremendous success," he recalled.
"That led me to think that perhaps we could have another year to try to empty the concentration camps."
Mr Benenson immersed himself in the fledgling organisation, personally going on research missions to various countries. At one point he posed as a British folk artist to be allowed to enter Haiti.
By the end of the decade, the first Secret Policeman's Ball was being held, with comedians from Monty Python and Beyond the Fringe performing for Amnesty's benefit.
As its profile grew, so too did the controversy surrounding it.
The candle symbolises those still facing abuse, Mr Benenson said
When Amnesty exposed human rights abuses by the South African security service, Boss, its London offices were attacked.
At the same time, it also forged a policy of impartial, independent campaigning against abuses in Western countries.
That has most recently seen it criticise policies of the US government at Guantanamo Bay and the British government's anti-terror legislation.
In 1966, an Amnesty report on the treatment of Yemenis by British colonial forces led him to allege the group had been infiltrated by British intelligence agents.
He called for Amnesty to move its headquarters to a neutral country.
An independent investigation did not support his claim, prompting Mr Benenson to retire from the organisation.
In the 1980s he became the chairman of the newly-formed Association of Christians Against Torture, but by the middle of the decade returned to Amnesty as a speaker and campaigner.
Disagreements on policy continued, such as when he publicly disapproved of Amnesty's decision not to adopt Mordechai Vanunu, the Israeli nuclear scientist jailed for revealing the country's weapons program, as a prisoner of conscience.
Speaking on Amnesty's 40th anniversary, Mr Benenson paid tribute to the organisation's "many victories".
But he went on to warn: "The challenges are still great.
"Only when the last prisoner of conscience has been freed, when the last torture chamber has been closed, when the United Nations Universal Declaration of Human Rights is a reality for the world's people, will our work be done."
A public service will be held in Mr Benenson's memory, Amnesty has announced.