MacTutor
20th October
On this day in 1939 the three Polish mathematicians Rejewski, Rozycki and Zygalski began decoding German Enigma cipher messages from a station near Paris. World War II had begun about two weeks earlier.
On this day in 2014 Google released a Wren doodle.
On this day in 2014 Google released a Wren doodle.