Kate Middleton Wore a Plunging Lace Gown With Princess Diana's Tiara

As you may know, the king and queen of Spain are on an official royal visit to Britain right now. After Queen Letizia made a stylish arrival on Wednesday, Buckingham Palace celebrated with a formal state banquet (which was conveniently live-streamed). Of course, Kate Middleton was on hand for the elegant affair too—she opted to wear a plunging pink lace gown by Marchesa. 

To round out the black-tie look, she wore two pieces of royal jewelry: Princess Diana's tiara and Queen Elizabeth's diamond-and-ruby necklace. Could she look any chicer?

Scroll down to see what Kate Middleton and Queen Letizia wore to the state banquet at Buckingham Palace.