Dutch Prince Johan Friso has died after nearly a year and a half in a coma following a skiing accident in Austria, officials say.
He was hit by an avalanche in February 2012 and buried for 15 minutes.
King Willem-Alexander and Queen Maxima are said to be on their way home from a holiday in Greece.
“Prince Friso died from complications as a result of oxygen shortages during his ski accident on February 17, 2012,” a royal palace statement said.
He died on Monday morning in The Hague, the palace added.
His wife, Princess Mabel, is said to have spent her 45th birthday on Sunday at his bedside.