The man whose codebreaking may have helped to shorten the Second World War by two years met a grim reward: in 1952 Alan Turing was convicted simply for being gay and chemically castrated; a royal pardon came only in 2013, decades after his death

Here are two facts about the same man, and they sit badly together.

The first: Alan Turing’s work at Bletchley Park was crucial to the effort to break German encrypted communications, part of an intelligence achievement credited with shortening the war in Europe by years.

The second: the same country he helped defend prosecuted him over a consensual relationship with another man. I keep coming back to how neatly the first fact should have protected him from the second, and how completely it did not.

Alan Turing was a mathematician and one of the leading codebreakers at Bletchley Park during the Second World War. He developed important methods for attacking Germany’s Enigma cipher, helped design the British Bombe machines used to test possible Enigma settings and initially headed Hut 8, the section responsible for German naval communications.

Estimates of the wider impact vary, but the work of Bletchley Park and the intelligence produced from intercepted German communications is often credited with having shortened the war by about two years or more. That estimate applies to the wider codebreaking and intelligence operation, not to Turing’s work alone, and any precise number must remain speculative because no one can know exactly how the war would otherwise have unfolded. What is not in serious doubt is that the intelligence produced at Bletchley Park made a major contribution to the Allied victory.

Decades later, when the British government finally addressed what happened to Turing after the war, it leaned on exactly this record. David Cameron called him “a remarkable man who played a key role in saving this country in World War II by cracking the German Enigma code.” That is the debt Britain now publicly acknowledges it owed him.

In 1952, Turing was convicted of gross indecency after admitting to a consensual sexual relationship with another man. The legal charge concerned sexual acts between men rather than homosexuality as an identity, but the distinction offered little protection in practice. Gordon Brown, in his 2009 government apology, described the reality plainly: “In 1952, he was convicted of ‘gross indecency’ – in effect, tried for being gay.”

Turing was given a choice between imprisonment and probation conditional on hormone treatment. He accepted the latter and underwent a course of injections of a synthetic oestrogen, a punishment commonly described as chemical castration. His conviction also cost him his security clearance and prevented him from continuing his classified cryptographic work for the government.

In 1954, aged 41, Turing died from cyanide poisoning. Gordon Brown did not reach for cautious language when describing the injustice that preceded it. “The debt of gratitude he is owed makes it all the more horrifying,” he said, “that he was treated so inhumanely.” He closed with an apology on behalf of the government: “We’re sorry, you deserved so much better.”

The formal pardon came later still. Queen Elizabeth II granted Turing a posthumous royal pardon in December 2013, following a request from Justice Secretary Chris Grayling. That was more than sixty years after Turing’s conviction and almost sixty years after his death.

Grayling described Turing’s punishment as “a sentence we would now consider unjust and discriminatory and which has now been repealed,” and called the pardon “a fitting tribute to an exceptional man.”

The pardon, however, applied only to Turing. It did not itself erase or overturn his conviction, and it did not automatically pardon the many thousands of other men prosecuted under comparable laws. The Peter Tatchell Foundation cited an estimate of around 49,000 men convicted under gross-indecency and related laws criminalising consensual sexual activity between men.

Peter Tatchell, a human rights activist,  named the central problem directly. “It’s obviously a very bad legal principle to make law or give pardons on the basis of whether someone is famous or important, or not,” he argued. That is his position rather than a statement of settled legal doctrine, but Turing’s exceptional fame plainly helped make his case politically visible in a way that thousands of others’ cases were not.

The timeline shows how slowly the wider recognition came. Sexual activity between men was only partially decriminalised in England and Wales in 1967, thirteen years after Turing died. His individual pardon followed in 2013.

The broader measure popularly known as “Turing’s law” was announced in October 2016 and became law when the Policing and Crime Act received Royal Assent on 31 January 2017. It granted posthumous pardons to men convicted of qualifying abolished offences involving consensual same-sex activity that would not be criminal today. 

Turing’s great-niece Rachel Barnes wanted the recognition extended beyond her famous relative. “I consider it to be fair and just that everybody who was convicted under the Gross Indecency law is given a pardon,” she said. Her position treats Turing’s fame as an accident of history, not as a reason that he deserved justice more than the other men prosecuted under the same system.

The pardon formally acknowledged the injustice done to one man, but it did not quash his conviction or undo the hormone injections, the lost security clearance or his death at 41. Nor did it, on its own, extend the same recognition to the tens of thousands prosecuted under comparable laws.