kate middleton war horse gi Kate Middleton wows, cries at 'War Horse' premiereThe London premiere of “War Horse” was an emotional experience for birthday girl Kate Middleton (aka the Duchess of Cambridge, who celebrates her 30th birthday on Monday, Jan. 9).

According to director Steven Spielberg, Middleton teared up at the end of the film.

“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,” the director tells “BBC Breakfast.” “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.”

Middleton, however, was all smiles when she hit the red carpet with husband Prince William ahead of the screening. She garnered much praise for her black lace Temperley gown which was adorably accessorized by the prince with a black-trimmed bubble umbrella.

“I am so honored that the Duke and Duchess have chosen this for their first royal film premiere,” Michael Morpurgo, who wrote the children’s book on which “War Horse” is based, tells London’s Daily Mail. “She is such a beautiful young woman, so full of dignity. I am going to send her a copy of the book for her birthday.”

According to palace officials, Kate and Prince William plan to celebrate her birthday doing something “low-key and private.”

Posted by:Liz Kelly Nelson