Kate Middleton may not have planned a lavish celebration for her thirtieth birthday on Jan. 9, but the dress she wore on the eve of her birthday said it all.

Catherine, the Duchess of Cambridge, had a stunning start to her first birthday eve in the royal family. She attended the UK premiere of the film War Horse at the Odeon Leicester Square cinema in London on Jan. 8 in her usual striking style.

Kate donned a floor-length, full-sleeved black lace dress that added to her elegance and style statement on the red carpet.

Accompanied by her husband Prince William, the Duke of Cambridge, Kate teamed up her attire with a velvet clutch and accessorized with her engagement ring and a bracelet.

The UK premiere of the Steven Spielberg film was an aid of  The Foundation of Prince William and Prince Harry. Scroll down to view the pictures of the royal patrons at the film’s premiere.