Peter Sellers often improvised on set, and director Stanley Kubrick encouraged him. Many takes of Dr Strangelove were ruined by actors corpsing at Sellers’ antics.

With three roles in the film – as Group Captain Lionel Mandrake, American President Merkin Muffley, and Nazi physicist Dr Strangelove – his performance is nothing short of awe-inspiring. But my favourite moment of ad libbing is from the movie Lolita, where Sellers plays the pompous playright, Clare Quilty.

With the tiniest gesture – boredly checking his watch while his dance partner twirls – Sellers reveals his entire character. It’s a powerful reminder of how much information physicality alone can convey.