Prince George celebrates fifth birthday with big smiles

The palace has released a new photo of Prince George to commemorate his fifth birthday.

A shot of Prince George, taken after the christening of his brother Prince Louis, has been released by his parents to mark his fifth birthday. Source: Matt Porteous/PA

A picture of a smiling Prince George has been released as the third in line to the throne prepares to celebrate his fifth birthday on Sunday.

George, the oldest of Prince William and Kate's three children, was photographed in the garden of his home in Clarence House after the christening of his brother Louis in early July.

The new official picture, showing the prince grinning at something - or someone - off camera, was taken after the christening of Prince Louis by photographer Matt Porteous,

This shot of Prince George, taken after the christening of his brother Prince Louis, has been released by his parents to mark his fifth birthday. Source: Matt Porteous/PA

Porteous had also taken private pictures for William and Kate at the christening of two-month-old Louis earlier this month.

The picture, tweeted by Kensington Palace, came with a message of thanks from the duke and duchess.

Prince George recently started his first year of school. Source: AAP

"The Duke and Duchess of Cambridge are very pleased to share a new photograph of Prince George to mark his fifth birthday – thank you everyone for your lovely messages".

To mark the young royal's birthday, a new £5 coin has been issued by the Royal Mint, depicting St George and the Dragon on its reverse.

The young prince made his most recent appearance at the christening of Prince Louis at Clarence House, alongside his parents and siblings. Source: Matt Holyoak/AP

Prince George's last public outing was at the christening in The Chapel Royal at St James's Palace, alongside his parents and siblings.

That appearance marked the first time the family-of-five had been seen all together.

Prince Goerge, who as the Queen's great-grandson is third in line to the throne, has made several public appearances in the past 12 months, including on the balcony at Buckingham Palace for the Queen's official birthday celebrations in June. 

He also served as a page boy at the wedding of Prince Harry - his uncle - and Meghan Markle in May.

The Daily Mail has reported George is spending his birthday on the Caribbean island of Mustique in Saint Vincent and the Grenadines with his family.