Lord Shawcross, who led the British prosecution at the Nuremberg war crimes tribunal, has died aged 101.
Lord Shawcross was Britain's voice at Nuremberg
The barrister, who was attorney general in the post-war Labour Government, died peacefully at his home in Sussex, his secretary Greta Kinder said.
Lord Shawcross, the last-surviving member of Attlee's 1945 administration, was a controversial figure.
Britain's youngest ever King's Counsel and a confirmed socialist "for humanitarian reasons", Hartley Shawcross was elected to parliament in 1945.
Swiftly promoted to the post of attorney general, he prosecuted British traitors William Joyce and John Amery, and the so-called Acid Bath Murderer, John George Haigh, also faced Shawcross from the dock.
In December 1945, as Chief Prosecutor for the United Kingdom at Nuremberg, the freshly knighted Sir Hartley opened the British case against the Nazi leaders with a speech that lasted nearly five hours.
Hartley Shawcross: Britain's youngest ever King's Counsel
He called this international tribunal a novel procedure, but one that helped "provide as fair a trial as possible".
Shawcross also went before the Hague to state Great Britain's case against Albania after the mining of the British destroyers in the Corfu Channel.
Back in England, he followed Harold Wilson into the post of President of the Board of Trade, and held the post until the fall of the Labour Government in 1951.
Shawcross, who was born into a Rochdale mill-owning family, was known for dropping political bricks with regularity.
His biggest came during Labour's post-war political dominance.
Sir Hartley's apparent comment on his party as "the masters now" became part of political history, and he was pilloried as an arrogant aristocrat.
In fact, his words, "we are the masters at the moment", said during a technical bill, were taken out of context.
Sir Hartley Shawcross at the Nuremberg trials
He later said: "I've said a lot of bloody stupid things in my time, but I think that was perhaps the most stupid."
Giving up his practice at the bar in 1957, the following year Shawcross resigned his seat in the House of Commons and became estranged from the Labour Party.
Turbulent private life
He was dubbed Sir Shortly Floorcross, although he never joined the Conservatives. On being made a Life Peer in 1959, he sat in the House of Lords as a cross-bencher.
After a high-profile but often controversial career, during which he clashed several times with such infamous figures as Mr Molotov and Mr Vyshinsky, Lord Shawcross "decided just quietly to fade out of politics".
Lord Shawcross spoke his mind in the House of Lords
In demand as a committee member, during the 1960s and 1970s, he chaired in turn the Royal Commission on the Press, Thames Television and the Press Council.
From 1965, he was the Chancellor of Sussex University, near his country home.
Controversial in public, Sir Hartley suffered tragedy in private. His first wife killed herself after years of illness, and his second wife died after being kicked by a horse on the Sussex Downs in 1974.
Into his 10th decade, he surprised his family by marrying a third time. His memoirs written then revealed a lifetime of personal unhappiness and disillusionment, but his prominence in the worlds of law, business and politics reveals an idealist surely determined to leave his mark.