Kleenex for Kate as she sheds a tear at War Horse premiere

As the story of an unlikely friendship between a boy and his horse, it is an unashamed weepy designed to tug on the heartstrings.

And it certainly had the desired effect on the Duchess of Cambridge, who apparently cried from start to finish at last night’s royal premiere of Steven Spielberg’s new film, War Horse.

In an interview with BBC Breakfast today, the legendary director revealed that his actress wife, Kate Capshaw, had even been passing tissues to sobbing Kate.

‘I was sitting next to her and all I know is at one point my wife, who was sitting to my right, right in front of my face she passed a Kleenex ... I saw the Kleenex go across my face, arrive and stop but I didn't want to intrude on her experience watching War Horse so I never glanced over,’ he said. 'According to my peripheral vision her eyes were dabbed.'