12 February 1953: birth of Nabil Shaban, who played Sil in Vengeance on Varos (1985), Mindwarp (1986) and the Big Finish audio Mission to Magnus (2009).
ii) broadcast anniversaries
12 February 1966: broadcast of "The Sea Beggar", second episode of the story we now call The Massacre. Stephen continues his search for the Doctor, while the Huguenots look for Anne Chaplette to resolve the rumours of the planned mass killing.
12 February 1972: broadcast of third episode of The Curse of Peladon. The Doctor is condemned to trial by combat; he escapes but is recaptured. As he defeats Grun, shots ring out...
12 February 1977: broadcast of third episode of The Robots of Death. Dask/Taran Capel sends the robots to kill the remaining crew; the Doctor teams up with D84.
iii) date specified in canon
12 February 1554: execution of Lady Jane Grey, as almost seen in the 2010 Sarah Jane Adventures story Lost in Time.