17 December 1929: birth of Jacqueline Hill, who played the First Doctor companion Barbara Wright from 1963 to 1965 (she is the first regular cast member to actually appear on screen), and then returned to play Lexa in 1980.
17 December 2009: death of James Cairncross, who played Lemaitre in nThe Reign of Terror (1964) and Beta in The Krotons (1968-69).
ii) broadcast anniversaries
17 December 1966: broadcast of first episode of The Highlanders, introducing Fraser Hines as Jamie. The Doctor, Ben and the McCrimmon menfolk are captured by Redcoats in the aftermath of Culloden; Polly hides out with Kirsty McCrimmon.
17 December 1977: broadcast of fourth episode of The Sun Makers. Leela is rescued, Gatherer Hade thrown off the roof and the Collector disappears down the plug'ole.
17 December 2006: broadcast of Out of Time (Torchwood), the one with the accidentally time-travelling plane passengers from 1953.