Prince William turns 38 on Sunday, and was pictured at his Anmer Hall mansion on the Sandringham estate in Norfolk, where he has been staying with the Duchess of Cambridge, and their children Prince George, Princess Charlotte and Prince Louis.
In one image taken by Kate, William and his three youngsters sit on a tree-swing posing for the camera, and in another the light-haired brood clamber on top of their father as he lies grinning on the ground.
William, who is second in line to the throne, is just one of a number of royals who have celebrated birthdays during lockdown.
The Queen turned 94 and also marked her official birthday, the Duke of Edinburgh turned 99 earlier this month, while Louis turned two in April and Charlotte reached age.