Second son of Beatrix of the Netherlands and Claus von Amsberg; brother of King Willem-Alexander of the Netherlands
According to Wikipedia, Prince Friso of Orange-Nassau was the younger brother of King Willem-Alexander of the Netherlands. Prince Friso was a member of the Dutch Royal Family, but because of his marriage without an Act of Consent in 2004, he lost his membership of the Dutch Royal House and was no longer in the line of succession to the throne.
Prince Friso of Orange-Nassau is affiliated with the following schools: