Happy birthday Princess Kate! And happy new-royal-portrait-day to the rest of us. In honor of Kate Middleton's 43rd birthday on January 9, Prince William shared a new, black-and-white portrait of the Princess of Wales on the couple's official Instagram, with a sweet message in the caption.

William praised Kate for her "remarkable" strength in the post released on Thursday, Jan. 9 Prince William is celebrating his love and admiration for Kate Middleton as she marks her 43rd birthday. In a message posted to the couple's social media,

On Jan. 9, Kate Middleton celebrated her 43rd birthday. Her husband, Prince William, publicly acknowledged the special day on Instagram. Alongside a new black and white photo of the princess wearing a white blouse, a black overcoat, jeans, and a checkered scarf, William wrote, “To the most incredible wife and mother.”