John Louis of Nassau-Hadamar (Dillenburg, August 6 1590- Hadamar, March 10 1653)
He was the son of van John VI, Count of Nassau-Dillenburg and his third wife Johannetta of Sayn-Wittgenstein.
When his father died in 1606, Nassau was divided amongst his 5 sons. William Louis received Nassau-Dillenburg, John received Nassau-Siegen, George received Nassau-Beilstein, Ernst Casimir received Nassau-Dietz and John Louis Nassau-Hadamar.
He married in 1617 with Ursula of Lippe, daugther of Simon VI, Count of Lippe. they had 14 children of which 6 survived infancy :
When John Louis was 28 years old, the Thirty Years' War broke out. He tried in vain to keep Nassau-Hadamar out of the war. His lands suffered from the passage of all kinds of Imperial and Protestant troops, which plundered and requistioned them into poverty. Highly indebted, John Louis was forced to sell Esterau to Peter Melander Graf von Holzappel in 1643.
John Louis was raised a Calvinist, as was sent in 1629 by his brothers as a diplomat to Vienna to negociate a truce with Emperor Ferdinand II. Here John Louis converted to Catholicism under influence of Wilhelm Lamormaini. John Louis was much appreciated by the Emperor for his diplomatic skills. In 1638 he successfully led the peace negociations in Cologne and Munster. In 1645 he was added to the Imperial delegation under Maximilian von und zu Trauttmansdorff who negociated the Peace of Westphalia. By 1647 he had replaced Trauttmansdorff as head of the Imperial delegation, and it was he who finalized the treaty.
For this, he was awarded the Order of the Golden Fleece by King Philip IV of Spain.
Ferdinand III, Holy Roman Emperor made him a Prince (Fürst) and gave him a large som of money.