Kate Middleton wore a diamond tiara that hadn’t seen the light since the 1930s.

Middleton, 41, attended a state banquet Tuesday night at Buckingham Palace in London hosted by King Charles III and Queen Camilla in honor of South Korean President Yoon Suk Yeol and first lady Kim Keon Hee’s state visit to the United Kingdom.

But one accessory captured the public’s attention: the dazzling diamond tiara atop the head of the Princess of Wales that she had never before worn publicly.