A stylish birthday it is for Kate Middleton who turns 30-years-old Monday. During her last moments of 29, the Duchess of Cambridge stepped out in an Alice Temperley gown, stunning the crowd yet again.

Middleton looked ravishing in a white gown with black lace overlay by Alice Temperley, one of her favorite UK designers, at the red carpet premiere of Steve Spielberg's War Horse in London. The fitted gown featured a V-neck and subtle fishtail skirt. Kate completed the look with a black clutch and simply jewelry.

This was a decidedly sexier style for Middleton. The black lace and slim fit proved extra sultry. Kate herself oozed glamor with a darker, smoky eye and loose waves.

Prince William was dressed in his red carpet best - a dapper black tuxedo. Unfortunately the weather did not hold out for the handsome duo. Luckily, William came prepared with an oversize umbrella to keep Kate dry.

She and William were the guests of honor at the UK launch. The event at Odeon in Leicester Square was being held in the name of charity, specifically the Foundation of Prince William and Prince Harry. Kate herself is also a patron.

Director Steven Spielberg spoke about the couple's attendance, saying:  It's a very prestigious honor because they represent an entirely new era in British royalty that has the entire world excited

When they came to America, that was one of the most exciting events, I think, that we've enjoyed for some time, so it's such an honor to be here in the UK to be able to meet them and to be able to show them, and all of us, 'War Horse.'

I am delighted that the UK Premiere of War Horse is in aid of 'The Foundation of Prince William and Prince Harry' and that this special occasion is attended by two of the patrons, Their Royal Highnesses, The Duke and Duchess of Cambridge, he added.

'War Horse' encapsulates for me a timeless personal story of courage. The movie, which I am proud to say was filmed here in Great Britain, deals with the discovery of humanity against conflict, and celebrates bravery, loyalty, tenacity and hope.

Following Kate and William on the red carpet was the film's equine star - a chestnut colt named Joey, who had his own PR personnel and a manure scooper, reports The Daily Mail.

Middleton will celebrate her 30th birthday with a low-key and private affair, surrounded by family and friends.

Palace officials stated that the Duchess of Cambridge's birthday celebration will be a low-key and private, according to The Associated Press. This is in stark contrast to press reports claiming Middleton would celebrate with an '80s-themed fete, complete with cocktails and karaoke.

An intimate celebration is probably the most appropriate choice. Middleton is not only marking a milestone, but she is also in training to be queen one day.

She's done very well, playing a very good supporting role to Prince William and complementing him as part of a team, commentator Robert Jobson said of her first months as a royal. We've not seen much of her, but when she's in public she has performed with aplomb, added Jobson, who wrote William and Kate: The Love Story.