Alan Turing was a World War II code-breaker. He was also gay.

Fifty-five years after the mathematician committed suicide, Downing Street has apologised for the “appalling” way in which he was treated because of his sexuality.

According to Winston Churchill, Turing made the single biggest contribution to Allied victory in the war against Nazi Germany.

His pivotal role in cracking intercepted messages helped the Allies to defeat the Nazis in several crucial battles.

BBC: Alan Turing Profile