Kate borrows Queen's diamonds for charity gala

The Duchess wore a dazzling diamond necklace loaned by the Queen. Credit: Doug Peters/Doug Peters/EMPICS Entertainment

The Duchess of Cambridge returned to the spotlight as she joined a star studded guest list for a fundraising night in aid of the National Portrait Gallery.

Kate stepped out for her first engagement of the year wearing a dark-coloured Jenny Packham floor length dress.

The night was billed as a black-tie do with a "sparkle" and the Duchess followed the theme by wearing a dazzling diamond necklace loaned by the Queen.

The Duchess of Cambridge arrives for The Portrait Gala 2014. Credit: Ian Vogler/The Daily Mirror/PA Wire

The fabulous piece was a wedding gift given to the Queen to mark her marriage to the Duke of Edinburgh in November 1947.

Known as the Nizam of Hyderabad it was created by Cartier in the 1930s and has been worn by the monarch throughout her life and for many formal portraits.

Among the guests for the gala dinner was actress Elizabeth Hurley, rock star Bryan Adams, actor Alan Rickman and artist Grayson Perry.