Thanks to the lovely Robert Ross (https://twitter.com/RobertWRossEsq), I stumbled across this picture from 1990, the year of Dame Agatha’s centenary. To celebrate, Joan Hickson and David Suchet attended celebrations in Torquay, dressed as Miss Jane Marple and Monsieur Hercule Poirot, respectively.
Dame Christie was against the characters ever meeting in her narrative (after all, even if they had reason to meet, there’s very little chance they would like each other!). However, they do have various connections, proving they exist in the same world – as this lovely website points out.
Still, we can all savour the one time when our Poirot and Marple did get to know each other. (Excepting the encounter between Tony Randall and Margaret Rutherford in The Alphabet Murders, but let’s not discuss that…)