Mr Entwistle said quitting was the "honourable" thing to do as he had to take responsibility as editor in chief of the BBC for what Lord Patten, chairman of the BBC Trust, said was "unacceptable shoddy journalism".
He has lasted just 54 days in the job. Mr Entwistle's decision plunges the BBC into its deepest-ever crisis and leaves it leaderless at a time of mounting questions over its journalism.
You know who got this story right? Brass Eye.