25 April 1923: birth of Paul Whitsun-Jones, who played the Squire in The Smugglers (1966) and the Marshal in The Mutants (1972).
ii) broadcast anniversaries
25 April 1964: broadcast of "The Screaming Jungle", third episode of the story we now call The Keys of Marinus. The second Key is hidden in a jungle full of mobile carnivorous plants.
25 April 1970: broadcast of sixth episode of The Ambassadors of Death. The Doctor finds that the aliens are keeping the original astronauts hostage, but is kidnapped by Carrington on his return.