New Princess Charlotte photos mark her first birthday

Four new photographs of Britain's Princess Charlotte playing at her family's country home were released by the royal family on Sunday to mark her first birthday.

The photographs were taken by her mother, Kate, last month at Anmer Hall, the secluded house in Norfolk, eastern England, where the family spends much of its time.

Prince William and Kate were "happy to be able to share these family moments ahead of their daughter's first birthday" on Monday, their Kensington Palace office wrote on Twitter.

"We hope that everyone enjoys these lovely photos as much as we do," it added.

Charlotte is pictured in two different but matching floral patterned dresses -- one pink, one blue, with a cardigan on top.

In one of the shots, she is pushing a baby walker full of wooden bricks in the garden.

In another, she is holding a children's sound and action book which appears to be "The Wheels On The Bus" by British author David Ellwand.

William and Kate have been keen to protect the privacy of Charlotte and her brother, two-year-old Prince George.

The little girl, who is fourth in line to the throne, has only been seen in a few photographs since her birth, mainly released by royal officials.

Most recently, she was pictured on her great-grandmother Queen Elizabeth II's knee in a photograph of the youngest members of the royal family to mark the monarch's 90th birthday last month.