 The Order of the Garter once held services at St George 's Chapel , Windsor Castle , but they became rare in the 18th century . The annual Garter Services , discontinued in 1805 , were revived by King George VI in 1948 and have become an annual event . Each June , on the Monday of Royal Ascot week ( also known as Garter Day ) , the members of the Order , wearing their habits and garter insignia , meet in the state apartments in the Upper Ward of Windsor Castle . When any new Knights of the Garter are due for installation , an investiture ceremony is held at a Chapter of the Order in the Throne Room of Windsor Castle on the morning of Garter Day . This ceremony is attended by all Knights Companions of the order , wearing the ceremonial habits and garter insignia , and also by their wives . The wording of the oath sworn by the new knights at this ceremony and of the Admonitions addressed to them in turn by the prelate and chancellor of the order when the several items of insignia are placed upon them are extremely similar to the traditions of the past . 
