Prince Bernhard of Lippe (1872–1934)
Prince Bernhard of Lippe (Bernhard Kasimir Wilhelm Friedrich Gustav Heinrich Eduard; Oberkassel, 26 August 1872 – Munich, 19 June 1934) was a member of the Lippe-Biesterfeld line of the House of Lippe.
He is most notable for being the father of Prince Bernhard of Lippe-Biesterfeld, the prince consort of Queen Juliana of the Netherlands.
Pieter van Vollenhoven
Pieter van Vollenhoven Jr. (born April 30, 1939) is the husband of Princess Margriet of the Netherlands and a member, by marriage, of the Dutch Royal House.
Princess Marilène of Orange-Nassau, van Vollenhoven
Princess Marilène of Orange- Nassau, van Vollenhoven- van den Broek( née Marie- Hélène Angela van den Broek; 4 February 1970) is the wife of Prince Maurits of Orange- Nassau, van Vollenhoven, and was thereby member of the Dutch Royal House until King Willem- Alexander's accession in 2013 rendered Prince Maurits too distantly related to the reigning monarch.
She remains a member of the larger Dutch Royal Family.
Princess Marianne of the Netherlands
Princess Marianne of the Netherlands, Princess of Orange- Nassau(" Wilhelmina Frederika Louise Charlotte Marianne"; 9 May 1810 – 29 May 1883), was a member of the House of Orange- Nassau.
Prince Pieter-Christiaan of Orange-Nassau, van Vollenhoven
Prince Pieter-Christiaan Michiel of Orange-Nassau, van Vollenhoven (born 22 March 1972), is the third son of Princess Margriet of the Netherlands and Prof. Pieter van Vollenhoven.
Before the succession of his cousin Prince Willem-Alexander as King, he was a member of the Dutch Royal House and twelfth in line to the throne.
With Willem-Alexander's succession however, he is no longer a member of the Dutch Royal House, and is no longer in line to direct succession to the Dutch throne, but still retains his membership as a member of the Dutch Royal Family
Princess Anita of Orange-Nassau, van Vollenhoven-van Eijk
Princess Anita of Orange- Nassau( Anita Theodora, née van Eijk; born 27 October 1969) is the wife of Prince Pieter- Christiaan of Orange- Nassau, van Vollenhoven, and thereby member of the Dutch Royal Family by marriage.
Prince Floris of Orange-Nassau, van Vollenhoven
Prince Floris Frederik Martijn of Orange- Nassau, van Vollenhoven( born 10 April 1975) is the fourth and youngest son of Princess Margriet of the Netherlands and Pieter van Vollenhoven.
Prince Floris has three older brothers: Prince Maurits, Prince Bernhard, Prince Pieter- Christiaan
Princess Pauline of Orange-Nassau
Princess Pauline of Orange-Nassau ("Wilhelmina Frederika Louise Pauline Charlotte"; 1 March 1800 – 22 December 1806) was a Princess of the House of Orange-Nassau.
Prince Bernhard of Orange-Nassau, van Vollenhoven
Prince Bernhard Lucas Emmanuel of Orange-Nassau, van Vollenhoven (born 25 December 1969) is the second son of Princess Margriet of the Netherlands and Pieter van Vollenhoven.
Before the succession of his cousin Willem-Alexander as King, he was a member of the Dutch Royal House and eleventh in the line of succession to the Dutch throne.
With Willem-Alexander's succession however, he is no longer a member of the Dutch Royal House, and is no longer in line to direct succession to the Dutch throne, but still retains its membership as a member of the Dutch Royal Family
Princess Annette of Orange-Nassau, van Vollenhoven-Sekrève
Princess Annette of Orange- Nassau, van Vollenhoven- Sekrève(" legal name:" Annette van Vollenhoven- Sekrève; born 18 April 1972) is the wife of Prince Bernhard of Orange- Nassau, van Vollenhoven, the second son of Princess Margriet of the Netherlands and Pieter van Vollenhoven.
Annette Sekrève was born in The Hague, the daughter of Ulrich Sekrève and his wife Jolanda de Haan( the de Haan belong to the Dutch patriciate).
She obtained her vwo diploma in 1991 and studied from 1991 till 1996 at Groningen University where she obtained an MSc degree in psychology.
It was at university that she met her future husband, Prince Bernhard.
The couple announced their engagement on 11 March 2000.
They married in July 2000.
The civil ceremony was performed on 6 July 2000 by the Mayor of Utrecht, Ms A. H. Brouwer- Korf, in the Spiegelzaal van het Paushuize, Utrecht.
The marriage was blessed two days later, on 8 July 2000, by Dr. Anne van der Meiden in the Cathedral of Saint Martin, Utrecht.
Annette then acquired the courtesy title" Her Highness, Princess of Orange- Nassau, van Vollenhoven" due to her status as the wife of a Prince of Orange- Nassau.
Since 2002, Princess Annette has worked as a counsellor at the AGO foundation in Amsterdam.
Princess Annette and Prince Bernhard have three children:
The family resides in Amsterdam and lead low- profile lives, with attendance only at major royal family events including King's Day.

Question: What is the date of birth of Prince Bernhard Of Orange-Nassau, Van Vollenhoven's father?
Answer: April 30, 1939