Queen Camilla and the Prince and Princess of Wales have all received historic royal honours, Buckingham Palace has announced.

Prince William becomes Great Master of the Order of the Bath.

Catherine is now a Companion of Honour, which recognises achievement in arts, medicine, sciences and public service.

And the Queen becomes the Grand Master of the Order of the British Empire, once held by the King’s father, Prince Philip.

The appointments to these historic royal orders have rewarded those at the centre of the Royal Family, at a time when both King Charles and Catherine have been receiving treatment for cancer.

They will be seen as an acknowledgement of those keeping up official duties when royal numbers are diminished, including recognising the efforts of the Queen, who at the age of 76 has been attending events on behalf of the King.

She becomes First and Principal Dame Grand Cross of the Most Excellent Order of the British Empire. Established in 1917, the Order honours a broad cross-section of civilian and military recipients.

Catherine, as she continues to recover from her health problems, becomes the first royal to be appointed as a Companion of Honour in the order’s 107-year history, in what will be seen as a show of support from the King who recommended her.

She joins a select group of people honoured for their contribution to public life, such as artists and creative figures, currently including Sir David Attenborough, Ian McEwan and Sir Elton John.

Prince William’s honour as Great Master of the Order of the Bath will see him taking on a role held by his father when he was Prince of Wales.

The Order of the Bath was established in the 18th Century as a reward for exemplary service in military or civilian life.

Meanwhile, the Duchess of Gloucester, a working royal at the age of 77, becomes a member of the oldest and most senior of the orders of chivalry, the Order of the Garter, which dates back to the 14th Century.

Lord Lloyd-Webber, who composed music for last year’s Coronation, also becomes a member of the Order of the Garter – which is limited to 24 companions, not including royal and foreign appointments, and is the personal gift of the monarch. Air Chief Marshal Lord Peach and Lord Kakkar, who has had a long career in medicine and public service, are similarly honoured.

Graham Smith, chief executive of the anti-monarchy group Republic, called the honours a “slap in the face for all the hardworking people who get awarded MBEs, OBEs and CBEs”.

“The royals do very little in return for huge reward – but that’s never enough. Instead, we see our head of state handing out trinkets and medals to his own family in an act of breathtaking nepotism.”