Princess Catherine posted a rare photo of her youngest child

The mum usually takes her children's birthday portraits, but she broke tradition this year.

Instead, Kate and Prince William posted a photo taken by photographer Josh Shinner.

The sweet photo was taken at their family home in Norfolk earlier this month.

The young prince is sitting on a tree trunk and smiling in the adorable photo.

The prince has a gap in his front teeth, and fans of the royals couldn't help but point out how grown up he looked.

Fans couldn't help but point out how much Louis looks like Kate's father, Michael Middleton.

One said, "The Middleton are so strong."

One fan wrote, "Hasn’t he grown up so much! Happy birthday, Prince Louis."

"I had a smile like that when I was seven," another said.

Another added, "The same age as my toothless granddaughter."

"Hope the tooth fairy came. Happy birthday," another wrote.

"Wishing Prince Louis a very Happy 7th Birthday!" the royals wrote alongside the photo.

The Prince and Princess of Wales reportedly celebrated their son's birthday at their home in Norfolk.

They skipped the royal's Easter Sunday mass to spend time together as a family.

The family has been keeping a low profile in recent months, with Prince Louis making his last public appearance on Christmas Day.

The youngest prince joined his family at Sandringham Estate on Christmas Day. Louis and his siblings, Prince George and Princess Charlotte, greeted members of the public on Christmas Day.