Alan Turing: The Man Who Saved Millions and Was Destroyed by the State

On March 31, 1952, Alan Turing walked into a Cheshire courtroom. He was 39 years old. He had helped win the Second World War. That morning, he pleaded guilty to gross indecency. His crime: a consensual relationship with another man.

The World Turing Built

Alan Mathison Turing was born in London on June 23, 1912. From early childhood, his mind worked differently. He taught himself calculus at age fifteen. His teachers found him odd. His peers found him awkward. He found most of them uninteresting.

In 1931, Turing entered King's College, Cambridge. He read mathematics. He excelled. In 1936, he published a paper that changed everything. It described a theoretical device — now called the Turing machine. It laid the foundation for all modern computing.

Then came the war. In September 1939, Turing joined the Government Code and Cypher School at Bletchley Park, Buckinghamshire. The Germans used a cipher machine called Enigma. It produced codes considered unbreakable. Turing disagreed.

Working with Gordon Welchman and a team of analysts, Turing developed the Bombe. This electromechanical device could systematically test Enigma settings. By 1941, Bletchley was reading German naval signals with growing regularity. Historians estimate the work at Bletchley shortened the war by two to four years. It may have saved fourteen million lives. That estimate comes from historian Sir Harry Hinsley, official historian of British intelligence.

Turing also contributed to breaking the Lorenz cipher, used for Hitler's highest-level communications. He traveled to the United States in 1942 to share methods with American cryptanalysts. His influence stretched across the entire Allied intelligence effort.

After the war, Turing worked at the National Physical Laboratory in London. He designed one of the earliest stored-program computers, the Automatic Computing Engine. Later, at the University of Manchester, he helped develop the Manchester Mark 1. In 1950, he published his famous paper Computing Machinery and Intelligence. It introduced what became known as the Turing Test — a benchmark for machine thinking that researchers still debate today.

The Prosecution

In January 1952, Turing's Manchester home was burgled. He reported it to police. During their investigation, officers discovered that Turing had a relationship with 19-year-old Arnold Murray. Both men admitted the relationship. Both were charged.

The charge was gross indecency under Section 11 of the Criminal Law Amendment Act 1885. This was the same law used against Oscar Wilde in 1895. It criminalized sexual acts between men in private as well as in public. Consent was irrelevant. Age, within adult bounds, was irrelevant. The act itself was the crime.

Turing did not hide. He saw nothing shameful in what he had done. His solicitor reportedly found his client's openness alarming. Turing confirmed the relationship clearly in his police statement. He apparently believed the law would not apply seriously to someone of his standing and contribution. He was wrong.

On May 31, 1952, Turing was convicted. He chose probation over prison. The condition: he must undergo hormonal treatment. Doctors administered synthetic estrogen injections. The stated purpose was to reduce sexual drive. The treatment lasted a year. It caused physical changes including gynecomastia. Turing described the experience in letters with a kind of wry detachment. But those close to him saw a different man.

His security clearance was revoked. The Government Communications Headquarters, successor to Bletchley, barred him from consultancy work. He had given Britain its most valuable wartime secret. Britain gave him a criminal record.

Turing was not alone in this. Between 1885 and 1967, tens of thousands of men were prosecuted under the same law in England and Wales. Many lost careers, families, and homes. Some were imprisoned. Some died by suicide. The prosecutions continued methodically, decade after decade, sustained by a state that treated same-sex intimacy as a public health problem.

To understand the broader pattern of persecution that LGBTQ+ people faced across Europe in this era, including the use of criminal law as a systematic tool of suppression, see our piece on The Pink Triangle: From Nazi Persecution to Symbol of Pride.

June 1954: An Ending Without a Verdict

On June 7, 1954, Turing's housekeeper found him dead. He was 41. A half-eaten apple lay beside his bed. A post-mortem found cyanide poisoning. The coroner recorded suicide.

Some historians have questioned this verdict. Andrew Hodges, whose 1983 biography Alan Turing: The Enigma remains the standard account, accepts suicide as the most plausible conclusion. Turing had been conducting cyanide experiments in his home laboratory. His mother, Sara Turing, argued throughout her life that her son's death was accidental — that he died from inhaling fumes during his experiments. She published her own biography of him in 1959.

We do not know with certainty. What we know is the sequence: persecution, chemical alteration, professional exclusion, and then death at 41. Turing left no note.

What Came After

Britain decriminalized consensual sex between men over 21 in 1967, under the Sexual Offences Act. The Wolfenden Report had recommended this ten years earlier, in 1957. It took Parliament a decade to act.

Turing received no pardon during his lifetime. His reputation recovered slowly through academic channels. Hodges's biography brought him to wider public attention in 1983. In 1994, a building at Manchester University was named after him. In 1999, Time magazine listed him among the hundred most important people of the twentieth century.

In 2009, British Prime Minister Gordon Brown issued a formal apology on behalf of the government. The statement acknowledged that Turing had been treated appallingly. It stopped short of a formal pardon.

That pardon came in December 2013. Queen Elizabeth II granted it under the Royal Prerogative of Mercy. The legal conviction itself was not erased — only set aside symbolically. In 2017, the Alan Turing Law came into effect. It provided posthumous pardons to approximately 49,000 men convicted under historical gross indecency laws in England and Wales. Scotland enacted equivalent provisions the same year.

The Bank of England placed Turing's portrait on the fifty-pound note in 2021. The note entered circulation on June 23 — his birthday.

Turing's case became one of the most visible arguments for decriminalization movements worldwide. It illustrated something that reformers had argued for decades: that criminal law could be turned against people who posed no threat to anyone. The contrast between his contribution and his treatment was too stark to ignore. His name appears in parliamentary debates on decriminalization across multiple countries, cited as evidence of what the law could do when it operated without proportion or mercy.

The question of how legal systems across different countries have treated LGBTQ+ people — and how those systems are still changing — remains a live one today. Our overview of 7 Countries Where LGBTQ+ Rights Are Changing Fast in 2026 maps some of those continuing shifts.

What the Record Shows

Turing's story is well documented. Hodges's biography draws on letters, official records, and interviews with colleagues. The Bletchley Park archives have been progressively declassified since the 1970s. The National Archives in Kew hold the court records from the 1952 prosecution.

Some gaps remain. Turing was a private man. He wrote relatively little about his emotional life. His letters are precise and sometimes playful, but rarely confessional. We know the facts of his prosecution. We know less about how he experienced the years that followed.

What the record does show is a pattern. Turing was not targeted because he was Turing. He was prosecuted because the law applied equally to everyone — or tried to. The detectives who interviewed him in 1952 were not hunting a war hero. They were following standard procedure. The machinery of prosecution was ordinary. That, perhaps, is the most disturbing part.

The historian David Leavitt, writing in The Man Who Knew Too Much (2006), notes that Turing's case was unremarkable in legal terms. Thousands of men faced identical charges in the same decade. Most of them have no biographies. No notes were placed on banknotes in their memory. Their names are largely lost.

Turing's visibility today is partly a function of his genius. But the law did not distinguish between genius and ordinariness. It punished both with equal efficiency. That is what reformers, historians, and courts have since been asked to reckon with — not one exceptional case, but a systematic practice applied to ordinary people across decades.

He built the machines that think. The state that employed him then took nearly everything else. What remained was the work — and eventually, seventy years on, an image on a banknote, and a law bearing his name.