Twin baby joy for Brad Pitt and Angelina Jolie

Iconic superstars, high-profile humanitarians and now proud parents of six children: Brad Pitt and Angelina Jolie's romance could only have been forged in Hollywood.

The birth of Pitt and Jolie's twins -- a boy and a girl -- at a hospital in the south of France late Saturday is the latest chapter in a story that has transfixed celebrity-watchers since the couple became an item in 2005.

The couple -- who are among the highest paid stars in Hollywood, commanding 10-20 million dollars a film -- share three adopted kids and three birth children, a multicultural family with multiple homes that celebrates the traditions of the birth-countries of all their offspring.

Pitt, 44, was by Jolie's side for the births, by caesarean operation, of Knox Leon and Vivienne Marcheline at a clinic in Nice, reports said.

Gynaecologist Michel Sussmann told People magazine: "The babies are doing well. The operation went just perfectly."

"Angelina is in very good spirits. Brad Pitt was at her side. He was there and all was well."

The couple, who met while filming "Mr. and Mrs. Smith" in 2005, have seen their relationship flourish despite frenzied tabloid attention and relentless speculation about a possible split.

Much of that is attributable to the maelstrom that erupted three years ago when it became clear that Pitt and his ex-wife Jennifer Aniston were separating. Press immediately portrayed Jolie, 33, as the home-wrecking "other woman" behind the break-up.

But Oscar-winner Jolie has vehemently denied having an affair with Pitt while he was still in a relationship with Aniston, although in a 2006 interview with Vogue she admitted falling in love with her co-star during "Mr and Mrs Smith".

"Whether it was shooting a scene or arguing about a scene or gun practice or dance class or doing stunts -- anything we had to do with each other, we just found a lot of joy in it together and a lot of real teamwork," Jolie said.

"And it took until, really, the end of the shoot for us, I think, to realize that it might mean something more than we'd earlier allowed ourselves to believe," Jolie said.