The Duchess of Gloucester executed the perfect curtsy at the VE Day thanksgiving service at Westminster Abbey on Thursday.
Danish-born Birgitte, 78, who is married to the late Queen Elizabeth II's cousin, Prince Richard, was seen making the formal greeting to the King and Queen as the senior royals left the Abbey.
Royal ladies normally bob down into a low curtsy and bow their heads in public if they're seeing the monarch for the first time that day. For men, the greeting is normally a neck bow.
The royals arrived in reverse order of precedence at the service, with the Duke and Duchess of Gloucester and the Duke of Kent seated first.
They were followed by the Duke and Duchess of Edinburgh, the Princess Royal and Vice Admiral Sir Tim Laurence, then the Prince and Princess of Wales, and lastly the King and Queen.
The Gloucesters also joined Their Majesties at the first Buckingham Palace garden party of the year on Wednesday, where the Duchess wore a pillbox-style hat designed by King's Foundation and CHANEL Millinery student, Jessica Turley.
Meet the Gloucesters
Birgitte first met Prince Richard, the younger son of Prince Henry and Princess Alice, in the late 1960s in Cambridge, where he was a student.
Before marrying into the royal family, she worked as a secretary at the Royal Danish Embassy in London.
The couple wed on 8 July 1972 at St Andrew's Church in Northamptonshire, with the bride wearing a high-collar, long-sleeved gown designed by Norman Hartnell.
The Duke and Duchess have three children, Alexander, Earl of Ulster, Lady Davina Windsor and Lady Rose Gilman, born in 1974, 1977 and 1980 respectively.
The couple carry out full-time working duties and support a number of their own patronages and organisations.
The Duchess of Gloucester also made history as the first non-blood royal, not married to the monarch or the heir, to be made a Royal Lady of the Garter in 2024.