gowns, but the red mantles returned in the 17th century under King Charles I. When the knights were renamed, the mantles were abandoned. The military knights now wear the old military uniform of an "army officer on the unattached list": black trousers with red stripe, a red double-breasted swallow-tailed coat, gold epaulets and brushes, a cocked hat with a plume, and a sword on a white baldric. Robes and insignia Members Order's ceremonial occasions For the Order's ceremonial occasions, such as the annual Garter Day, the members wear elaborate vestments and accoutrements, which include: The mantle is a vestment or robe worn by members since the 15th century. Once made of wool, by the 16th century it was made of velvet. The mantle was originally purple, but varied during the 17th and 18th centuries between celestial blue, pale blue, royal blue, dark blue, violet, and ultramarine. Mantles are now dark blue and lined with white taffeta. The mantles of the Sovereign, the Prince of Wales, and Royal Knights and Ladies end in trains. The heraldic shield of St George's Cross encircled by the Garter is sewn onto the left shoulder of the mantle, but the Sovereign's mantle instead has the star of the Order. Attached to the mantle over the right shoulder are a dark red velvet hood and surcoat, which have lost all function over time and appear to the modern observer simply as a splash of colour. The hat is a Tudor bonnet of black velvet with a plume of white ostrich and black heron feathers. The collar is worn around the neck, over the mantle and is secured with white ribbons tied in bows on the shoulders. Like the mantle, it was introduced in the 15th and 16th centuries. Made of pure gold, it weighs 30 troy ounces (0.933 kg). The collar is composed of gold heraldic knots alternating with enamelled medallions, each showing a rose encircled by the Garter. During the reign of Henry VII (1485–1509), commencing at the termination of the Wars of the Roses, each garter surrounded two roses – one red for the House of Lancaster and one white for the House of York – but he changed the design to encircle the Tudor rose alone, a combination of both forms. Today one of the most visible representations of the collar forms part of the monarch's heraldic achievement on the gates of Buckingham