In the three portraits, George is playing outside wearing a soccer t-shirt in two and a green polo in the middle image. The images were captioned: "🎈⚽️ Happy Birthday Prince George! The Duke and Duchess of Cambridge are very pleased to share new photographs of Prince George to mark His Royal Highness's sixth birthday."
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"This photograph was taken recently in the garden of their home at Kensington Palace by The Duchess of Cambridge," the post continued. "Thank you everyone for all your lovely messages!"
On the second photo, showing George on holiday with his family, his aunty and uncle wrote: "Happy Birthday 🎂🎈 Wishing you a very special day and lots of love!"
Since opening their own Instagram, Meghan and Harry have publicly wished Prince William, Princess Charlotte, Prince Louis and now Prince George a happy birthday (They did not have their own Instagram during Kate Middleton's birthday on January 9.)
For Louis's birthday in April, they commented: "Happy Birthday Louis! Sending lots of love from both of us 🎂🎈 xo."
They wrote a similar message for Charlotte's birthday in May, commenting: "Happy Birthday, Charlotte! 🎂🎈 Lots of love, H and M xo."
In June for William's birthday, they commented their most formal response, "Happy Birthday to the Duke of Cambridge!"
According to The Sun, Prince George celebrated his birthday on the Caribbean island of Mustique, a tropical isaland, which the family last visited in summer 2018 and have visited most years since 2008, including a few trips with Kate's parents.
"They are going to Mustique again," a source told the publication, saying that the Duke and Duchess go back to the location because of its privacy and the fact that Kate used to holiday there with her family when she was young.
"It is incredibly private and incredibly discreet but not remote. They know and trust the staff who work there and they are creatures of habit," they explained. “Kate used to go there, the Middletons used to go there. The family love it.”