King Charles has long been asked to make the Princess of Wales an Order of the Garter.

King Charles has made two major appointments ahead of Garter Day on Monday.

The 75-year-old monarch has appointed former MI5 director general Baroness Manningham-Buller as Chancellor of the Order of the Garter and Tory peer and former insurance broker Lord Ashton of Hyde as the Master of the Horse, a ceremonial role in charge of the Royal Mews on state occasions.

Lady Manningham-Buller, who succeeds the Duke of Abercorn on his retirement, is the first female Chancellor of Britain’s oldest and most senior order of chivalry since the office’s inception in 1475.

It comes as increasing calls have been made for the Princess of Wales, who is currently undergoing cancer treatment, to be made a member of the Order of the Garter.

The Order of the Garter – Britain’s oldest and most senior Order of Chivalry – is celebrated annually with a procession and service in the grounds of Windsor Castle. This year’s service will take place on Monday, June 17.

The Office of Master of the Horse dates back centuries and was originally responsible for the Sovereign’s horses, carriages and, as a historic consequence, travel arrangements.

Now largely ceremonial, the role remains titular head of the Royal Mews. The Master of the Horse is present when the Royal Mews supports State occasions, for example, the current Master of the Horse, Lord de Mauley, rode in the Coronation Procession of His Majesty The King. The holder of the role rides on Trooping the Colour.

The role of Chancellor is among the highest-ranking titles in the Order and was held by The Bishops of Salisbury and Oxford for nearly 500 years.

Both appointments are in The King’s gift and are effective from Tuesday, June 18.