So do the girls fill the gap where their man should be? Certainly the camera lingers over them as they share both a bed and their past histories. Sienna Miller remains resolutely contemporary, but at least looks as though she has blood, bone and muscle. Keira Knightley, on the other hand, never loses her cool self-consciousness. Her particular brand of beauty — pristine, boyish-limbed and brittle — is the sort which appeals most to fashion editors. In repose, the face can be exquisite, but when she smiles or laughs we are suddenly confronted with the jagged grin of a pumpkin at Hallowe’en. Neither ultimately convinces us, and our attention wanders instead to the background of London in the Blitz, which is quite wonderfully recreated.

But there’s another problem, one caused by our more general cultural obsession with youth. The superficiality in most biopics is compounded by the lack of adultness and weight in so many contemporary screen actors. Miller and Knightley, along with Cillian Murphy, who plays William Killick, Vera’s war hero husband, come across as children who have been let loose in their grandparents’ walk-in wardrobes. Dwarfed by their surroundings, they appear to be playing at grown-ups — an impression enhanced here by the naughty, incessant smoking. Laurence Olivier and Vivien Leigh, those darlings of the Brit-pack from another era, once slipped into the characters of Nelson and Emma Hamilton like hands into tailored gloves. It seems that when it comes to biopics now, we must be content with mittens.