“The sitting monarch is able to appoint both men and women, making them either knights or ladies of the garter.
“To that end, in 1994 Princess Anne was appointed to the order. However, instead of becoming known as a lady, she requested a knight.”
Ms Walters explained: “This distinction was made because Ladies of the Garter didn’t have the same status as their male counterparts.
“While knights became companions, ladies did not. By choosing to become a Knight of the Garter, Anne is held in the same rank as her brothers.”
The Order of the Garter is the most senior order of chivalry in the United Kingdom and membership is traditionally granted in recognition of outstanding public service, national contribution, or personal service to the Queen.
Membership is limited to the Queen and the Prince of Wales as well as only 24 living members at one time.
Most members of the Royal Family do not count towards the limited 24 and are instead appointed as Royal Knights and Ladies Companions rather than Knights and Ladies Companions.
The Spanish king and queen said: “Dear Aunt Lillibet, we are deeply saddened to hear about the passing away of dear uncle Philip.
“In these sad moments, we would like to send you our most heartfelt condolences on behalf of the government and people of Spain, and all our sympathy and support.
“We will never forget the moments that we shared with him and the legacy of service and dedication to the Crown and the United Kingdom by your side.
“Our thoughts and prayers are with Your Majesty and the whole family.”