John William Friso
Prince of Orange
Reign	8 March 1702 – 14 July 1711
Predecessor	William III
Successor	William IV
Prince of Nassau-Dietz
Reign	25 March 1696 – ca. 1702
Predecessor	Henry Casimir II
Prince of Orange-Nassau
Reign	ca. 1702 – 14 July 1711
Successor	William IV
Stadtholder of Friesland and Groningen
Reign	25 March 1696 – 14 July 1711
Predecessor	Henry Casimir II
Successor	William IV
Born	14 August 1687 Dessau, Anhalt
Died	14 July 1711(1711-07-14) (aged 23) Hollands Diep, between Dordrecht and Moerdijk
Burial	25 February 1712 Grote of Jacobijnerkerk, Leeuwarden
Spouse	Landgravine Marie Louise of Hesse-Kassel ​ ​ (m. 1709)​
Issue	Amalia, Hereditary Princess of Baden-Durlach William IV, Prince of Orange
House	Orange-Nassau
Father	Henry Casimir II, Prince of Nassau-Dietz
Mother	Princess Henriëtte Amalia of Anhalt-Dessau
Military service
Battles/wars	War of the Spanish Succession Siege of Ostend Battle of Oudenarde Siege of Lille Crossing of the Scheldt Sieg of Ghent Battle of Malplaquet Siege of Mons Siege of Douai

John William Friso (Dutch: Johan Willem Friso; 14 August 1687 – 14 July 1711) became the (titular) Prince of Orange in 1702. He was the Stadtholder of Friesland and Groningen in the Dutch Republic until his death by accidental drowning in the Hollands Diep in 1711.^[1]

Friso was the son of Henry Casimir II, Prince of Nassau-Dietz, and Princess Henriëtte Amalia of Anhalt-Dessau who were both first cousins of William III. As such, he was a member of the House of Nassau (the branch of Nassau-Dietz), and through the testamentary dispositions of William III became the progenitor of the new line of the House of Orange-Nassau.^[2] He was educated under Jean Lemonon, professor at the University of Franeker.^[3]

With the death of William III of Orange, the legitimate male line of William the Silent (the second House of Orange) became extinct. John William Friso, the senior agnatic descendant of William the Silent's brother and a cognatic descendant of Frederick Henry, grandfather of William III, claimed the succession as stadtholder in all provinces held by William III. This was denied to him by the republican faction in the Netherlands.^[4]

The five provinces over which William III ruled – Holland, Zeeland, Utrecht, Gelderland and Overijssel – all suspended the office of stadtholder after William III's death. The remaining two provinces – Friesland and Groningen – were never governed by William III, and continued to retain a separate stadtholder, John William Friso. He established the third House of Orange, which became extinct in the male line in 1890. His son, William IV of Orange, later became stadtholder of all seven provinces.^[5]

John William Friso's position as William III's heir general was opposed by King Frederick I of Prussia, who also claimed (and occupied) part of the inheritance (for example Lingen). Under William III's will, Friso stood to inherit the Principality of Orange. However, the Prussian King Frederick I also claimed the Principality of Orange in the Rhône Valley, of which he later ceded the territory to France.^[6]

On coming of age in 1707, John William Friso became a general of the Dutch troops during the War of Spanish Succession, under the command of the Duke of Marlborough, and turned out to be a competent officer. He was present at the Siege of Ostend, commanded Dutch infantry at the Battle of Oudenarde, the Siege of Lille, and the Battle of Malplaquet, while leading all operations at the Siege of Mons. The prestige that he acquired from his military service should have favored his eventual elevation as stadtholder in the remaining five provinces. However, in 1711, when traveling from the front in Flanders to meet the King of Prussia in The Hague in connection with his suit in the succession dispute, he drowned on 14 July when the ferry boat on the Moerdyk was overturned in heavy weather. His son was born six weeks after his death.^[7]

On 26 April 1709, Friso married Princess Maria Louise of Hesse-Kassel (1688–1765), daughter of Charles I, Landgrave of Hesse-Kassel, and granddaughter of Jacob Kettler, Duke of Courland. They had two children.^{[citation needed]}

• Monuments in Moerdijk and Strijensas, on both sides of the historic ferry crossing across the Hollands Diep, commemorate the drowning of Johan Willem Friso.^[8]
• The Regiment Infantry Prins Johan Willem Friso (RI PJWF) is named in his honour.^{[citation needed]}
• Central Royal Military Band of the Netherlands Army "Johan Willem Friso" is named in his honour.^{[citation needed]}

• Louis IX, Landgrave of Hesse-Darmstadt and Countess Palatine Caroline of Zweibrücken – Became the most recent common ancestors of all reigning hereditary European monarchs in 2022 when Elizabeth II died and her son, Charles III became king.
• Christian IX of Denmark and Louise of Hesse-Kassel – Common ancestors of many reigning hereditary European monarchs
  • Descendants of Christian IX of Denmark

• Pieter Lodewijk Muller (1881), "Johann Wilhelm Friso", Allgemeine Deutsche Biographie (in German), vol. 14, Leipzig: Duncker & Humblot, pp. 275–276