Harry Hallowes, who died two years ago aged 79, was an Irishman who lived in a makeshift shack in a small corner of Hampstead Heath. He holed up there for so long that in 2007 he was awarded the title deed. Perhaps predictably, this eccentric hermit was christened “Britain’s richest tramp” by the media.

Hampstead (★, 12A, 103 mins), a romantic comedy loosely inspired by this real life story, sees Brendan Gleeson playing Hallowes stand-in Donald Horner, who finds his solitary existence rudely interrupted. First, by Diane Keaton’s American widow Emily Walters, who becomes intrigued by the man living an artisan loaf’s throw away from her flat in a well-appointed Hampstead mansion block, and then by property developers keen to get their grubby mitts on Donald’s patch of squatted land.