see more

TILBURG, NETHERLANDS - APRIL 27: Prince Constantijn and Princess Laurentien of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

TILBURG, NETHERLANDS - APRIL 27: Prince Constantijn and Princess Laurentien of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

see more

TILBURG, NETHERLANDS - APRIL 27: Prince Maurits and Princess Marilene of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

TILBURG, NETHERLANDS - APRIL 27: Prince Maurits and Princess Marilene of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

see more

TILBURG, NETHERLANDS - APRIL 27: Prince Bernhard and Princess Annette of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

TILBURG, NETHERLANDS - APRIL 27: Prince Bernhard and Princess Annette of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

see more

TILBURG, NETHERLANDS - APRIL 27: Prince Pieter-Christiaan and Princess Anita of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

TILBURG, NETHERLANDS - APRIL 27: Prince Pieter-Christiaan and Princess Anita of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

see more

TILBURG, NETHERLANDS - APRIL 27: Prince Floris and Princess Aimee of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)

TILBURG, NETHERLANDS - APRIL 27: Prince Floris and Princess Aimee of The Netherlands attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)