Important reason Kate Middleton will 'break royal tradition' tomorrow

There's an important reason why Kate Middleton will 'break royal tradition' tomorrow.

Royal fans will no doubt already know it's the Princess of Wales' 43rd birthday on Thursday (9 January) and, due to the tumultuous past year she faced health-wise, it's no surprise she'll be wanting to celebrate the occasion in a more low-key fashion.

It's been reported that Kate typically tends to celebrate the special day with her husband, Prince William, and their three children: Prince George, Princess Charlotte, and Prince Louis at their Norfolk home, Anmer Hall.

Kate Middleton will be celebrating her 43rd birthday tomorrow (9 January) (Samir Hussein/WireImage)

The family-of-five usually stays at Anmer Hall for the first few weeks of the new year.

However, this year, they'll reportedly be breaking royal tradition by heading back to their full-time home in Windsor, Adelaide Cottage, according to Hello!

Neither Kate or William has explained why they decided to cut their stay in Norfolk short, but it could have something to do with their three children's return to school, in Berkshire, which is just a matter of minutes away from the cottage.

And that's not the only reason tomorrow's celebration will be reportedly different from last year's.

Royal correspondent Jennie Bond recently told OK! via The Mirror: "This time last year, the princess must have been anxious - and probably in pain - as she geared up for her planned abdominal surgery, which took place a few days after her 42nd birthday.

"That, of course, was followed by the shock of her cancer diagnosis, so this will be the perfect opportunity to celebrate."

The Princess of Wales will reportedly be spending her birthday with her family at Adelaide Cottage (Samir Hussein / Contributor / Getty Images)

Former royal butler, Grant Harrold, has also echoed this.

Speaking to Tyla on behalf of JeffBet, he said: "Obviously this is a significant birthday for Kate, last year’s events threw her future into the universe. The fact she’s had a difficult year and now celebrating this birthday, she’ll probably celebrate even more so and look forward to the year ahead for a positive year to come, and towards next year. It’s an important birthday but more on a personal level, last year is likely a year she’ll want to forget and move on from."

This year, however, will be 'memorable in so many ways'.

Bond continued: "It will mark the start of a new and hopefully happier year, and the end of one that has been brutal for the whole family.

"While some women might find the prospect of turning 43 a bit daunting, Catherine will, I am sure, be delighted that she is able to enjoy her birthday in comparatively good health, though of course she is still recovering.

"Every day must now be extra precious for the Princess, and every birthday a cause for grateful celebration."

Tyla has reached out to Kensington Palace for comment.