21 February

On 21 February 1968, the Sixth Doctor left Henry Gordon Jago and Professor George Litefoot in the Red Tavern in London, mistakenly believing that it was the 1890s. (AUDIO: Voyage to the New World)

Exactly ten years later, workers in Mexico City uncovered the sacrificial stone at the base of the Great Temple of the Aztecs. (PROSE: The Left-Handed Hummingbird)

On the same day in 1865, while on duty in Gable, West Virginia, Captain Will Johnson wrote a letter to his lover, Claire Bartlett. (PROSE: Blood and Hope)

Behind the scenes

 * 1900 - Actor Sydney Arnold was born.
 * 1924 - Actor George Selway was born.
 * 1931 - Actor Kenneth Seeger was born.
 * 1964 - Actor Huw Higginson was born.
 * 1970 - Episode four of Doctor Who and the Silurians was first broadcast on BBC1.
 * 1970 - Part six of TV Comic story The Arkwood Experiments was first released in issue nine hundred and forty-seven.
 * 1976 - Episode four of The Seeds of Doom was first broadcast on BBC1.
 * 1980 - The novelisation of The Invasion of Time was first published by Target Books.
 * 1981 - Episode four of The Keeper of Traken was first broadcast on BBC1.
 * 1981 - Composer Ron Grainer, who wrote the original Doctor Who theme, died.
 * 1996 - Filming on Doctor Who, the 1996 made-for-television film, completed.
 * 2007 - Issue twelve of  Battles in Time, including comic story Beneath the Skin, was first released by GE Fabbri Ltd.
 * 2013 - Designer Raymond Cusick, who co-designed the Daleks, died.
 * 2013 - Doctor Who Adventures comic story Toothache! was first released in issue three hundred and eight.