There are few royal services which are more steeped in tradition than . On Monday, and will be joined by other members of in Windsor for the annual procession.

Royals who have been inducted into the Order are or at state dinners, as well as a metal Garter Star below their medals. However, for Garter Day, the full ceremonial uniforms are worn for the service at St George's Chapel in . There are many details which make up the uniform, all of which have interesting secret meanings.

The dark blue robes (or mantles) worn by Knights and Ladies of the Garter are eye-catching and feature the heraldic shield of St George's Cross which is sewn onto the left shoulder of the mantle. Interestingly though, the King's mantle is different as it instead has the star of the Order.

The hat worn is a Tudor bonnet with ostrich and black heron feather plumes attached at the top.

Another part of the uniform is the gold collar which is worn around the neck and tied to the mantle with white ribbons.

Finally, the Garter itself is worn around the left calf by Knights and around the left arm by Ladies. It is a buckled dark-blue velvet strap which bears the Order's motto (Honi soit qui mal y pense, which translates to "Shame on him who thinks evil of it") in gold lettering.

As the oldest order of chivalry in the United Kingdom, there are several important rules which explain who can be added as membership is limited to the monarch, the Prince of Wales and a maximum of 24 living members.

The Order of the Garter also includes Supernumerary Knights and Ladies (e.g. members of the British Royal Family and foreign monarchs. Any new appointments are left entirely up to the King's discretion and are typically in recognition of a national contribution to public service, or for personal service to the monarch.

The two most recent members of the Royal Family to be added to the Order were Queen Camilla in 2022 and the Duchess of Gloucester in 2024.

Other members of the Royal Family, such as the Princess of Wales and the Duchess of Edinburgh, watch the service inside St George's Chapel and later take part in a carriage procession around the castle grounds.