The pictures were taken by Danish royal photographer Franne Voigt, and were released on the royal family’s official Instagram account.
The images were captioned: 'It is a pleasure for the Crown Prince couple to share a new picture of the whole family on the occasion of the Royal Highness Crown Prince’s 50th birthday.'
Prince Frederik and Princess Mary’s eldest child, Prince Christian, is now 12, while Princess Isabella is 11 and twins Princess Josephine and Prince Vincent are 7.
Princess Mary recently brought a room to tears with her moving speech at her husband's 50th birthday bash.
'You invited me into your world and the world of the Danes, after we had only known each other for a short time. And there were, indeed, many unsure steps when we started our common journey, side-by-side and separated at one and the same time,' she said.
'We dared to lose that part of our heart, which we allowed the other to hold in their hands.
'It takes courage to dare, but without daring we lose what could have been. I am so happy that you swept me off my feet and that we dared to fall for each other — not for a moment, but for life.'