Kate Middleton surprises tourists and royal fans outside Buckingham Palace – video

The Duchess of Cambridge dropped in to see the Queen

Tourists and royal fans who were visiting Buckingham Palace this week were given the biggest surprise when they saw the Duchess of Cambridge drive past. Kate was spotted behind the wheel, driving into the palace, most likely to drop in to see her grandmother-in-law the Queen. Judging by the blacked-out rear windows of her car, it's possible that the Duchess was accompanied by her daughter Princess Charlotte, three, and her baby boy Prince Louis. Scroll down for link to video.

Charlotte finished nursery for the year on Wednesday, while her older brother Prince George's school term comes to an end on Thursday. So the little Princess may have been treated to a dip in the palace pool to celebrate the start of the Christmas holidays. Kate often visits Buckingham to use the Queen's swimming pool, which is where her children have been learning how to swim.

Scroll to second post to see Kate arriving at the palace:

A video posted by Instagram user melissagrflx shows the Duchess waving to the crowds of tourists as she pulled up at the palace gates. Kate, 36, looked casual in a cream top and had her hair down. Another car followed closely behind, presumably her personal protection officers. Melli told HELLO!: "We went there without knowing that anything special would happen that day. There were many people waiting for the Changing of the Guards when she came to the palace. I really didn't expect to see her. It was a short but exciting moment."

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The Cambridges will be spending Christmas in Norfolk this year with Her Majesty and the rest of the royal family. William and Kate will stay at their lavish county pile, Anmer Hall, which is just a few minutes' drive away from the 'big house' – Sandringham House. Prince Harry and Meghan will also celebrate with the Queen, and reports claim that the monarch has also extended an invite to Meghan's mum Doria Ragland.

See the Cambridges' Christmas card from last year:

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Christmas is a very traditional affair for the royals; they usually attend a Christmas Day service at St Mary's Magdalene Church followed by lunch at the Queen's home, after which they tune in to watch her televised speech. They may also go for a country walk and have afternoon tea following the Queen's speech.

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