George, Charlotte, Louis mark 'best papa' William's birthday: 'We love you'

Princess Kate joined her children, Prince George, Princess Charlotte and Prince Louis, to celebrate 'best papa' William on his 44th birthday and Father's Day. 

On June 21, the official social media channels of the Prince and Princess of Wales released a new, unseen portrait featuring William and his daughter, Charlotte.

The father-daughter duo was seen lovingly posing for the camera.

"Happy birthday and Father’s Day to the best Papa in the World! We love you very much. C, G, C & L," the sweet caption reads. 

Fans in the comments section extended warm wishes to the future monarch, William.

One wrote, "Princess Diana would be so Proud of the Man he is, Happy Birthday to the Prince of Wales."

"Charlotte is such a papa's girl," another fan penned.

"Hope you have a fantastic birthday with your loved ones, William," a social media user said.