Angelina Jolie had a "simple" 37th birthday party.

The event took place on June 4 at her rented Wentworth Estate mansion in Surrey, England, which reportedly costs $24,000 a month to rent.

A source told Us Weekly: "It was a very small bash - just the family at home. They didn't go out or do anything.

"Just a simple one at home with a cake. No frills, but they're all really happy at the moment. Everyone's doing good."

Angelina purchased a waterfall for the Moneyball star's 48th birthday and Christmas presents in December last year.

She is currently in England preparing for her role in Disney's 'Maleficent', based on the villain from 'Sleeping Beauty'.

Brad, meanwhile, will return to Budapest around June 20 to begin two weeks of reshooting for 'World War Z'.

While he is away filming the movie, an insider told the publication that their children Maddox, 10, Pax 8, Zahara, 7, Shiloh, 5, and twins Vivienne and Knox, 3 will stay in the United Kingdom.

They said: "The kids will stay back in the UK with Angelina."