LONDON - Britain's royal family released a photograph on Saturday of a smiling Princess Charlotte, one of Queen Elizabeth's great-grandchildren, the day before the princess celebrates her sixth birthday.

Charlotte is fourth in line to the British throne and is the only daughter of Prince William, Elizabeth's grandson, and his wife Kate, Duchess of Cambridge.

In the picture Charlotte is shown wearing a blue dress with a pink floral pattern and pink buttons, and she stands with her arms stretched out and her hair falling over her shoulders, smiling at the camera.

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The photograph was taken by Kate earlier on Saturday in Norfolk, eastern England, where the family currently live.

Charlotte was born in London on May 2, 2015, and is William and Kate's second child. Charlotte's elder brother Prince George was born in July 2013 and her younger brother Prince Louis was born in April 2018. (Reporting by David Milliken; Editing by Daniel Wallis)