Count John VI of Nassau-Dillenburg was the second son of William the Rich and the younger brother of William the Silent. He has a special place in the history of the Netherlands because he is the male-line forefather of the House of Orange which ruled that country until 1898.
John VI of Nassau-Dillenburg was a Count of Nassau in Dillenburg. Other names he had were Jan VI or Jan de Oude ("John the Elder", to distinguish him from his 2nd son, "John the Middle", and his grandson "John the Younger"). He was the second son of Count William I of Nassau-Dillenburg and his second wife Juliane of Stolberg-Wernigerode, and brother of William I of Orange.
He was the principal author of the Union of Utrecht.