Princess Eugenie upheld a sentimental royal tradition on Saturday.
After tying the knot with Jack Brooksbank on Friday, the royal’s wedding bouquet — filled with Lily of the Valleys, Stephanotis pips, hints of baby blue thistles, white spray roses, trailing ivy and myrtle — was placed on the Grave of the Unknown Warrior at Westminster Abbey in London on Saturday.
In doing so, Eugenie, 28, is following a royal tradition that dates back nearly a century, starting with Queen Elizabeth’s mother, Elizabeth Bowes-Lyon, who became the Duchess of York (and later Queen Elizabeth) when she married the future King George VI (then the Duke of York) in 1923.
As the royal made her way into Westminster Abbey for her wedding ceremony, she — without previous intention to do so — laid her bouquet on the Grave of the Unknown Warrior (also called the Tomb of the Unknown Warrior), in memory of her older brother Fergus Bowes-Lyon, who was killed in action in the Battle of Loos in 1915 during World War I.
- Can’t get enough of PEOPLE’s Royals coverage? Sign up for our newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!
Since then, nearly every major royal bride has had her bouquet placed at the Grave of the Unknown Warrior, whether they married at Westminster Abbey or not. The Queen did, as did her sister Princess Margaret in 1960 and her cousin Princess Alexandra in 1963. In the next generation, Princess Anne, Princess Diana, Sarah, Duchess of York and Sophie, Countess of Wessex carried on the tradition in 1973, 1981, 1986 and 1999, respectively. Kate Middleton did it following her wedding in 2011, as did Meghan Markle in May.
RELATED VIDEO: Princess Eugenie Arrived in the Same Car Kate Middleton Used at Her Own Royal Wedding
Westminster Abbey, which houses the body of an unknown soldier who died during World War I, went on to share a photo of Eugenie’s bouquet on the grave on Twitter.
Westminster Abbey also explained the special significance behind Eugenie’s use of myrtle in her bouquet.
Queen Victoria was given a bouquet containing myrtle by her husband Prince Albert’s grandmother during one of the couple’s visits to Germany. That same year, the couple planted a sprig of myrtle at their new home, where it continues to grow today.
When Victoria’s eldest daughter, Princess Victoria, got married in 1858, she became the first royal bride to carry myrtle, which signifies a bride’s innocence, in her bouquet.