Despite continuing cancer treatment, the King is expected to appear alongside William, just weeks after Prince Harry’s television interview in which he claimed his father had stopped communicating with him and that he was unsure how long the King had left.

Charles and William will later proceed to the Abbey’s Lady Chapel of King Henry VII for the formal installation. There, the Prince of Wales will take an oath as Great Master, followed by the induction of five new Knights Grand Cross. The ceremony includes a traditional offering of gold and silver by the sovereign at the altar. The newly installed knights will then present their own offerings and place their swords on the altar.

Founded by King George I in 1725, the Most Honourable Order of the Bath is believed to have roots dating back to the 8th century. Its name comes from the symbolic ritual of bathing, which was originally part of the spiritual purification required before knighthood. Candidates once had to undergo practices such as fasting, prayer, and vigils in preparation for their honour.

During Queen Elizabeth II’s reign, it became customary to bestow honorary Grand Cross titles upon visiting heads of state. One of the most well-known recipients was former US president Ronald Reagan.

The service is traditionally held every four years, with the Great Master present each time and the monarch attending every eight years. In April of last year, King Charles appointed the Princess of Wales as the first Royal Companion in the history of the Order of the Companions of Honour, recognising her contributions to public life and the arts.

At the same time, Queen Camilla was named Grand Master and First or Principal Dame Grand Cross of the Most Excellent Order of the British Empire.