Turing gets posthumous apology

Some argue that Alan Turing was as important as Winston Churchill in helping Britain defeat Nazi Germany in World War II.

Alan Turing was a computer genius who played a central role in successful British efforts to break Enigma, the German high command's codes.

However, he was not rewarded with honours by the state, or public adulation.

Instead he was persecuted because of his homosexuality, opting for chemical castration rather than imprisonment after conviction for gross indecency.

Two years later, in 1954, he took his own life.

Now, after thousands signed a petition calling for the government to apologise, Britain's prime minister, Gordon Brown has done so.

He said he was deeply sorry that Mr Turing had been treated inhumanely under the homophobic laws of the time.

Andrew Hodges is a biographer of Alan Turing and a mathematician at Oxford University.

Mathematician Dr Norman Routledge was a friend of Alan Turing.

He begins by reading an extract from a letter that Alan Turing had written to him after his arrest.

First broadcast 11 September 2009