Kate Middleton ‘declined a historic royal invitation,’ taking a firm stance that broke with tradition.

As Princess of Wales, Kate is pretty much a permanent fixture at every major event in her role as one of the most senior royals. But before her 2011 wedding, tradition often dictated that before being married into the royal family, attending family ocassions such as Christmas and Easter was off the cards. In fact, Kate didn’t join an official royal Christmas celebration with William and the rest of his family until December 2011 – the Christmas after her wedding when she was first Duchess of Cambridge.

However, when it came to her sister-in-law Meghan Markle several years later, she was allowed to join royal Christmas with Prince Harry – despite the pair not being married – leaving people asking why the same offer hadn’t been extended to Kate. But according to a book, the late Queen did actually invite the princess to a festive event prior to her engagement to Prince William, but she turned it down.

In his biography Battle of Brothers, Robert Lacey claims the monarch broke from tradition and extended her first invitation to an unregistered partner for the family’s traditional Christmas lunch in 2006. But Kate, who was 24 at the time, is reported to have declined the historic request. In his book, he writes that Kate “would go to Sandringham on Christmas Day only when she was engaged”.

He explains: “By 2006, the couple had been dating seriously for the best part of five years. Yet when William invited Kate to join him that year at Sandringham for the Royal Family’s traditional Christmas lunch, she refused. It was the first time the Queen had extended such an invitation to an unregistered ‘girlfriend’, but Kate had her own take on that break with tradition: she would go to Sandringham on Christmas Day only when she was engaged and had a ring to prove it.”

However, despite now being a fully-fledged royal for almost 12 years, there is a major engagement Kate is set to miss next month – William’s third annual Earthshot Prize awards in Singapore. Many thought Kate would definitely be travelling to Asia for the annual event but the Mirror revealed she would not be attending, with royal sources later saying she decided to stay at home to support Prince George, who has school exams that week.

Kensington Palace has refused to comment on what exams future king George, 10, will be taking. However, the preliminary entrance exams for Eton College, known as ISEBs, occur at that time as the Earthshot Prize during the first week of November. Several other elite private schools also use the exams.