Kate Middleton and Prince William are back in Scotland. The Prince and Princess of Wales, who also go by the titles the Duke and Duchess of Rothesay when in Scotland, were attending the naming ceremony of HMS Glasgow at the shipyard of British aerospace manufacturer BAE Systems in Scotstoun on Thursday.

The royal headpiece is the one Kate has worn the most during her royal life and was also a favorite of her late mother-in-law, Princess Diana, who wore it on multiple occasions. According to the Court Jeweller, the special tiara is more than 100 years old and was originally commissioned from the jeweler Garrard by Queen Mary in either 1913 or 1914.