Kate Middleton and Prince William have shared a new photo of their youngest son Prince Louis in honor of his 6th birthday ...

"Happy 6th Birthday, Prince Louis! Thank you for all the kind wishes today," read the caption from Prince William and Princess Kate, with photo credit to the Princess of Wales. Why Kate Middleton ...

PEOPLE understands that the Prince and Princess of Wales decided to release the photo to acknowledge well-wishers who wished Prince Louis a happy birthday. "Happy 6th Birthday, Prince Louis!