Monday 23 June 2014 would have been Alan Turing's 102nd birthday. One of the 20th century's great mathematicians, Turing made profound contributions to a wide range of fields including computer science, artificial intelligence and mathematical biology. He also played a crucial role in the Allied codebreaking work at Bletchley Park during World War II, credited by some historians with shortening the conflict by two years.

More recently, much public attention has focused on the controversy surrounding his 1952 conviction for gross indecency under the punitive anti-homosexuality laws in force in Britain at the time: an official pardon was issued by the British government in December 2013. Turing's life and work has also inspired several representations on stage and screen, including the acclaimed play and BBC drama Breaking the Code and a forthcoming film, The Imitation Game, starring Benedict Cumberbatch and Keira Knightley.

To celebrate Turing's birthday, learn more about his contributions to mathematics with these Plus articles, and watch the video below, produced by the University of Cambridge to mark Turing's centenary in 2012, in which James Grime (who works alongside Plus as part of the Millennium Mathematics Project) gives an overview of Turing's story.