The Most Honourable Order of the Bath was established as a military order by Letters Patent of George I on 18 May 1725, when the Dean of Westminster was made Dean of the Order in perpetuity and King Henry VII's Chapel designated as the Chapel of the Order. However, the Order was a revival of an older custom going back to medieval times when part of the ceremony of knighthood included a ritual bath symbolic of spiritual purification and a vigil the night before receiving the honour. There is an account of this ceremony in the reign of Henry IV in 1399 and it was kept up until the time of Charles II, after which it fell into disuse.

The Order was enlarged in 1815 and three classes of knights were formed: Knights Grand Cross, Knights Commander and Companions. A small number of distinguished civilians were also admitted at this time and in 1847 a civil division of Knights Commander and Companions was added. As a result of the increased numbers after 1812, due in part to the Napoleonic wars, no installations took place in the chapel until 1913 when George V revived the service and the erection of stall-plates, banners and crests was begun again. The banner, crest and mantling of each GCB (Knight Grand Cross) hang above his stall until his death when they are returned to his family, but a copper stall-plate enamelled with his coat of arms remains as a permanent record. Knights may wait many years before a stall becomes vacant (for example Lord Mountbatten had to wait 17 years). Ladies were admitted to the Order in 1971 and Princess Alice, Duchess of Gloucester was the first Dame Grand Cross. HRH The Prince of Wales is the current Great Master of the Order and he and the Sovereign (whose stall plate is illustrated here) occupy stalls at the west end of the chapel at an installation. Overseas heads of state and other distinguished foreigners may be made Honorary members of the Order. Installation services usually take place every four years.

From the reign of James I a special badge with three crowns was appropriated to the Knights of the Bath and is probably an allusion to the three kingdoms of England, Scotland and Ireland, as is the motto Tria Juncta in Uno (three joined in one). Famous holders of the Order have included Nelson, Wellington, Earl Haig, Lord Kitchener and Viscount Montgomery of Alamein.

Colour prints of most of the stall plates can be purchased from the Abbey Library. For information on individual knights enquiries should be addressed to the Genealogist of the Order at the Central Chancery for the Orders of Knighthood, St James’s Palace, London SW1A 1BH.