The Duke and Duchess of Cambridge are likely to mark the occasion with a party and an official picture has already been released by Kensington Palace.
In the photograph he smiles as he leans towards the camera and William cannot help but laugh, as he holds his son in his arms.
The picture was taken by celebrated fashion photographer Mario Testino immediately after Princess Charlotte was baptised at the Church of St Mary Magdalene in Sandringham on 5th July.
The Cambridges will celebrate George`s birthday privately at Anmer Hall, their Norfolk home, as William is still settling into his new job as an East Anglian Air Ambulance helicopter pilot.
Prince George Alexander Louis of Cambridge, third in line to the throne and a future king, was born at St Mary`s hospital`s private maternity unit, the Lindo wing, at 4.24pm on July 22 2013, weighing 8lbs 6oz.
He made his public debut in front of the world`s media on the hospital steps one day later, wrapped in a white merino wool shawl, cradled in his proud parents` arms.
A great-grandchild to the Queen, he will be the 43rd monarch since William the Conqueror obtained the crown of England if, as expected, he follows reigns by the Prince of Wales then William.
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