Kate Middleton and Prince William have been busy sending out more thank you cards, this time on behalf of Princess Charlotte. The youngest royal celebrated her first birthday on 2nd May and to mark the happy occasion her mother released an adorable picture of the toddler in a pink dress.

The picture taken by Kate, was sent to the thousands of people who had sent birthday wishes to the princess. Jess Isle from Halifax, a fan of the royals shared the card on Twitter, after it arrived in the post.

The message on the card read: "The Duke and Duchess of Cambridge are most grateful for the very kind message you sent to Princess Charlotte on the occasion of her first birthday. It was most thoughtful of you and greatly appreciated."

The Royal family previously treated the Royal fans with a series of charming photos of Princess Charlotte, just before her first birthday, which were taken by Kate Middleton herself.

Princess Charlotte has reportedly received gifts and letters from 64 countries from around the world. The youngest child of Prince William and Kate Middleton has been given clothes, blankets, books and toys from schools, community groups and royalists, the Telegraph reported. Several government heads have also made charitable donations in Princess Charlotte's name.

"The Duke and Duchess of Cambridge are incredibly grateful for all the letters, gifts and good wishes they have been fortunate to receive in the year since Princess Charlotte was born," a spokesman for Kensington Palace said at the time.

The Duke and Duchess of Cambridge have had a lot to celebrate of late following the birth of Prince George and the arrival of his sister and more recently the couple marked their fifth wedding anniversary. And as the public shared in their happiness, flooding them with messages and gifts, the royals have been keen to express their gratitude personally.

Last week, Kate And William sent out a thank you card featuring a portrait of themselves to mark their wedding anniversary, taken by royal photographer Chris Jelf.

"The Duke and Duchess of Cambridge were so touched that you took the trouble to write as you did on the occasion of their 5th Wedding Anniversary,' the card read. "It really was most thoughtful of you and Their Royal Highnesses send you their warmest thanks and best wishes."