Louis of Nassau, Lord of De Lek and Beverweerd (1602 – The Hague, 28 February 1665) was a Dutch soldier. He was the illegitimate son of Margaretha van Mechelen and Maurice, Prince of Orange, and so a collateral member of the House of Orange-Nassau. He was a Lord of the heerlijkheid De Lek and Beverweerd. From his father he inherited the estate of Beverweerd; and when his older brother Willem died in 1627 he inherited his estate as well.^[1]

He joined the army which had claimed his brother William's life and served with distinction in 1629 in the battle near Den Bosch. In 1632 he was advanced to Colonel and after 1635 was in charge of a regiment. In 1640 during the battle for Hulst he prevented the cannons from falling into enemy hands. In the same year he was sent to Paris to advise the French king of the forthcoming marriage of the 14-year-old William II of Orange to the 9-year-old English Princess Mary Stuart. Also, when the young Prince proceeded to England to fetch his bride, he was accompanied by Louis of Nassau. In 1643 he became General-Major and Governor of the city of Bergen-op-Zoom.

Despite his mother's objections he married Isabella van Hornes in the spring of 1630 and from this marriage ten children were born. Lodewijk was highly regarded by his uncle, Prince Frederick Henry, and took part in the Prince's family life.

Louis was originally a supporter of his next of kin, the Princes of Orange. After the death of William II he made his peace with the anti-Orangist regents of the cities of the Dutch Republic and worked with the administration of Johan de Witt, becoming First Noble of Holland. In 1658 Louis of Nassau became Governor of Den Bosch and in 1660 was sent as a special ambassador to England. In addition to his representing the Dutch republic, two of his daughters were married to British noblemen. Emilia married the heir of the Duke of Ormonde and Elisabeth the Earl of Arlington, one of King Charles II's ministers. By 1662 he had forged an apparently strong relationship between England and the Dutch republic and returned to Holland where he died on 28 February 1665. ^[2]

He married Countess Isabella of Hornes in the spring of 1630, and had ten children.

He and Countess Isabella had three surviving sons:

He also had seven daughters of whom the two eldest were:

Louis of Nassau died in The Hague and was buried there, March 6, 1665, in de Great, or St. James Church.^[3] His descendants are buried in the family crypt at Ouderkerk aan den IJssel.