7 September 1917: death of Ewen Solon, who played Chal in The Savages (First Doctor, 1966) and Vishinsky in Planet of Evil (Fourth Doctor, 1975).
7 September 1959: birth of Rona Munro, so far the only person to have written TV stories for both Old Who and New Who. She wrote Survival, the very last story of the 1963-89 series (Seventh Doctor, 1989), and The Eaters of Light (Twelfth Doctor, 2017).
7 September 1960: birth of Christopher Villiers, who played Hugh Fitzwilliam in The King's Demons (Fifth Doctor, 1983) and Professor Moorhouse in Mummy on the Orient Express (Twelfth Doctor, 2014)
ii) broadcast anniversaries
7 September 1968: broadcast of episode 5 of The Dominators. The Doctor disposes of the invaders by planting their bomb on their own ship; but the Tardis is engulfed by lava...
7 September 1987: broadcast of first episode of Time and the Rani, starting Season 24. The Doctor unexpectedly falls off his exercise bike and regenerates; the Rani then captures him. Mel attempts to escape the bubble-traps but is caught.