5 Moments That Made Alan Turing the Father of Computer Science

Alan Turing became the figure widely considered the father of theoretical computer science through five identifiable turning points: a childhood book that opened his eyes to science, a 60-mile bicycle ride to boarding school, his leadership of Hut 8 at Bletchley Park, his prosecution in 1952, and the posthumous recognition that followed decades after his death.

Turing was born on 23 June 1912 in Maida Vale, London, and would go on to work as a mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. He is widely considered the father of theoretical computer science.

Moment 1: A book that opened his eyes to science (1922)

In 1922, Turing discovered Natural Wonders Every Child Should Know by Edwin Tenney Brewster, a book he credited with opening his eyes to science. Before that, his education had taken a fairly conventional path: he attended St Michael's primary school from age six to nine at St Leonards-on-Sea, and between 1922 and 1926 he was educated at Hazelhurst Preparatory School in Sussex. A single popular-science book, read at the right age, is often enough to redirect a curious mind—Turing's case is one of the clearest examples on record.

Moment 2: The 60-mile ride to Sherborne (1926)

At age 13, in 1926, Turing began attending Sherborne School, an independent boarding school in Dorset. On the first day of term that year, he rode his bicycle 60 miles from Southampton to Sherborne. It was at Sherborne that Turing formed a significant friendship with Christopher Collan Morcom, described as his first love. This period of his life combined physical determination with the intellectual and emotional bonds that would shape his character.

Turing went on to graduate from King's College, Cambridge, and earned a doctorate degree from Princeton University in 1938.

Moment 3: Leading Hut 8 at Bletchley Park (1940)

During World War II, Turing worked at Bletchley Park, Britain's codebreaking centre, where he led Hut 8, the section responsible for German naval cryptanalysis. He devised techniques for speeding the breaking of German ciphers, including improvements to the Polish bomba method. This work sat at the intersection of pure mathematical theory and urgent practical application—a pattern that would recur throughout his career.

After the war, Turing worked at the National Physical Laboratory, where he designed the Automatic Computing Engine, and in 1948 he joined Max Newman's Computing Machine Laboratory at the University of Manchester. He also wrote on the chemical basis of morphogenesis, predicting oscillating chemical reactions such as the Belousov–Zhabotinsky reaction.

Moment 4: Prosecution and its consequences (1952)

In 1952, Turing was prosecuted for homosexual acts and accepted hormone treatment as an alternative to prison. He died on 7 June 1954, aged 41, from cyanide poisoning. An inquest determined his death as suicide, but the evidence is also consistent with accidental poisoning. This moment marks the sharpest contrast in his story: a man who had helped shorten a war through mathematics was, within a decade, prosecuted by the same state he had served.

Moment 5: Apology, pardon, and lasting recognition

In 2009, British Prime Minister Gordon Brown made an official public apology for how Turing was treated. Queen Elizabeth II granted Turing a pardon in 2013. Turing's portrait appears on the Bank of England £50 note, first released on 23 June 2021—his birthday. A 2019 BBC series audience vote named him the greatest scientist of the 20th century.

Why these five moments matter

Taken together, these five moments trace a single arc: curiosity sparked by a book, determination proven on a bicycle, genius applied under wartime pressure, injustice suffered under the law, and recognition granted only after death. Turing's father, Julius Mathison Turing, worked with the Indian Civil Service of the British Raj, and his mother, Ethel Sara Turing, was the daughter of Edward Waller Stoney, chief engineer of the Madras Railways. This family background of engineering and administration seems to echo in Turing's own combination of rigorous theory and practical machine-building.

English phrases from Turing's story

• "He is widely considered to be the father of theoretical computer science." — useful for describing a founding figure in any field.
• "Turing devised techniques for speeding the breaking of German ciphers." — a pattern for describing technical innovation.
• "An official public apology for how Turing was treated." — vocabulary for discussing historical injustice and posthumous rehabilitation.
• "The evidence is also consistent with accidental poisoning." — a phrase for expressing scientific uncertainty in formal English.