Kate Middleton is the saving grace of the monarchy in more ways than one. In addition to pushing through her cancer diagnosis and showing up at royal events while she received chemotherapy, the Princess of Wales has also played a pivotal part in keeping Prince William and King Charles 's relationship healthy during the royal family's recent challenging times.

Kate Middleton, who is celebrating her 43rd birthday on Jan. 9, has proven herself to be the shiniest jewel of the British monarchy. The princess is married to Prince William, heir to the throne.

King Charles and Queen Camilla are wishing Kate Middleton a happy birthday! See the royal couple's tribute as the Princess of Wales turns 43.