The future king - whose birthday is July 22 - is likely to spend the weekend celebrating his big day with his parents, the Duke and Duchess of Cambridge.
Where does Prince George sit in terms of succeeding the throne?
Porteous shared the adorable shot, which was taken in the Clarence House garden, to Instagram today, writing in a caption, "Happy birthday Prince George 'It was a privilege to take this photograph of Prince George, and I am delighted that The Duke and Duchess have chosen to share it".
But George is the star of the royal show this week, as third in line to the throne behind his father, Prince William, and his grandfather, Prince Charles the Prince of Wales.
Trump dubs himself 'your favorite president' in response to hush money report
They shared the recording with Trump's lawyers as well, The New York Times reported, citing three people briefed on the matter. When questioned about the allegations, President Trump has denied the affair and said he had no knowledge of any payment.
Who can forget George's adorable christening pictures accompanied by his doting parents, William and Kate.
It has been an eventful year in the life of Prince George Alexander Louis of Cambridge.
It was also the youngest Prince's first official royal engagement since his birth on April 23, 2018.
When former US President Barack Obama and his wife Michelle visited England in 2016, they couldn't resist meeting George. On close inspection, the last button on George's shirt hasn't been done up. He started school at Thomas's Battersea, and the family moved from... Prince William, for one, occasionally looked exasperated at their antics.
Prince William was an RAF search and rescue pilot.