Thanks to Joe Twyman for this list: he suggested it because he was so distressed by a Twitter thread started by Jonn Elledge. Robert Boston had already proposed a Top 10 of biologically impossible parental relationships in drama, some of which feature here.
1. Pauline McLynn, 32 when she first played Mrs Doyle in Father Ted in 1995. Thanks to Jonn Elledge.
2. John Cleese, 36 when he first played Basil Fawlty in 1975. Nominated by Joe Twyman.
3. Keira Knightley, 14 in Star Wars: Episode I – The Phantom Menace in 1999. She was Sabe, the decoy for Queen Padme Amidala, played by Natalie Portman, who was 18; Knightley was chosen because she looked like her. Nominated by Conor Downey.
4. Lionel Jeffries, 42 when he played grandpa Potts, six months younger than Dick Van Dyke, his fictional son in Chitty Chitty Bang Bang, 1968. From Bob Melling, Wendy and Robert Boston.
5. Sean Connery, 59 when he played Harrison Ford’s father in Indiana Jones and the Last Crusade in 1989. Ford was 47. Nominated by Conor Downey and Robert Boston.
6. Maggie Smith, 37 when she was Aunt Augusta in Travels with my Aunt, 10 years younger than Alec McCowen, who played her supposed nephew (in fact, as we discover – spoiler alert – her son). Thanks to Anthony Nixon.
7. Angela Lansbury, 37 when she played the 35-year-old Laurence Harvey’s mother in The Manchurian Candidate, 1962. “Angela had some form in this area, having played Elvis Presley’s mum in Blue Hawaii, 1961, when Elvis was 26 and Angela 35,” said Graham Jones.
8. Anne Bancroft, 36 when she appeared as Mrs Robinson in The Graduate, and only six years older than Dustin Hoffman. From Darren Sugg, Paul Frame, Rhys Needham and John Peters.
9. William Hartnell, 55 when he starred as the white-haired Doctor in Doctor Who, 1963. Thanks to Leon Crosby and Increasingly Wright.
10. John Thaw, 32 when he filmed the first episode of The Sweeney, playing Jack Regan, Flying Squad detective. Dennis Waterman, his sidekick George Carter, was 26. Thanks to Matt Knight, who also nominated Eddie Murphy, 22 when Beverly Hills Cop, 1984, was filmed.
No room, because they are too well known, for Clive Dunn, 48 when he started playing Corporal Jones in Dad’s Army, or for Wilfred Brambell, 50 when Steptoe and Son started in 1962, and 13 years older than Harry H Corbett.
Honourable mention for Turmut Hoer, for pointing out that, by the age of 30, Alexander III of Macedon had created one of the largest empires in history, stretching from Greece to northwestern India.
Next week: Wizards.
Coming soon: Countries now in a different place, such as Bulgaria, which used to be where Ukraine is, and Benin, which used to be in what is now Nigeria.
Your suggestions please, and ideas for future Top 10s, to me on Twitter, or by email to firstname.lastname@example.org