Martin Luther King
From Tardis Wiki, the free Doctor Who reference
Martin Luther King was assassinated in 1968. This led to many riots in the United States of America. (AUDIO: The Age of Revolution)
In 2608, copies of the works of Martin Luther King were kept in the Depository. (AUDIO: The Diet of Worms)
Behind the scenes
Stock footage of a speech by Martin Luther King was used in the television story Remembrance of the Daleks.
During the Monk's invasion of Earth, a picture of Martin Luther King was shown on one of the screens inside the Cathedral. (TV: The Lie of the Land)