Question: When was the King of Prussia died under whom Friedrich Wilhelm Ernst Freiherr von Gaudi served as a Lieutenant General?

Context articles: Ernst von Bibra
Friedrich Wilhelm von Gaudi
Friedrich Wilhelm von Thulemeyer
Friedrich Wilhelm von Erdmannsdorff
Friedrich Wilhelm Quirin von Forcade de Biaix
Prince Friedrich Wilhelm of Prussia
Prince Friedrich Wilhelm of Lippe
Friedrich Wilhelm von Seydlitz
Frederick the Great
Götz von Houwald

Dr. Ernst Freiherr von Bibra (9 June 1806 in Schwebheim – 5 June 1878 in Nuremberg) was a German Naturalist (Natural history scientist) and author.
 Ernst was a botanist, zoologist, metallurgist, chemist, geographer, travel writer, novelist, duellist, art collector and trailblazer in ethnopsychopharmacology.
Friedrich Wilhelm Ernst Freiherr von Gaudi (Gaudy) (23 August 1725 in Spandau, Berlin – 13 December 1788 in Wesel) was a Prussian Lieutenant General who served Frederick the Great in the Seven Years' War.
Friedrich Wilhelm von Thulemeyer or Frederick William von Thulemeier was born or baptized on November 9, 1735.
 He died July 6, 1811, also in Berlin.
 In 1763 he was sent by Frederick the Great as a diplomat in the Republic of the Seven United Provinces.
 In 1784/85 he was one of the architects of a trade relations between the US and Prussia.
 In 1788 he became justice minister under Friedrich Wilhelm II of Prussia.
 Of particular importance is - even today - his collection of music prints.
Friedrich Wilhelm Freiherr von Erdmannsdorff (18 May 1736 – 9 March 1800) was a German architect and architectural theoretician, and one of the most significant representatives of early German Neoclassicism during the Age of Enlightenment.
 His work included Wörlitz Palace in the present-day Dessau-Wörlitz Garden Realm, one of the earliest Palladian buildings on the European continent.
 His most well-known student was Friedrich Gilly, the teacher of Karl Friedrich Schinkel.
Friedrich Wilhelm Quirin von Forcade de Biaix, baptized "Quirin Frideric de Forcade," aka "Friedrich Quirin von Forcade," aka "Frédéric Quérin de Forcade" (* 11 January 1699, Berlin; † 23 March 1765, Berlin) was a Royal Prussian Lieutenant General, the second son of a Royal Prussian Lieutenant General, an early Huguenot immigrant to Brandenburg-Prussia and a descendent of the noble family of Forcade.
 He was one of King Frederick the Great's most active and most treasured officers.
 Three times wounded and once left for dead on the battlefield, he bathed the Forcade de Biaix name in glory.
 Together with his wife, he fathered 23 children.
Prince Friedrich Wilhelm of Prussia (German: "Prinz Friedrich Wilhelm Viktor Karl Ernst Alexander Heinrich von Preußen" ; 12 July 18809 March 1925) was a member of the House of Hohenzollern, great-grandson of Frederick William III of Prussia.
Friedrich Wilhelm of Lippe (German: "Friedrich Wilhelm Ernst Viktor Alexander Prinz zur Lippe" ; born 7 September 1947) is a claimant to the headship of the House of Lippe.
Friedrich Wilhelm Freiherr von Seydlitz (3 February 1721 – 8 November 1773) was a Prussian officer, lieutenant general, and among the greatest of the Prussian cavalry generals.
 He commanded one of the first Hussar squadrons of Frederick the Great's army and is credited with the development of the Prussian cavalry to its efficient level of performance in the Seven Years' War.
 His cavalryman father retired and then died while Seydlitz was still young.
 Subsequently, he was mentored by the Margrave of Brandenburg-Schwedt, also known as the "Mad" Margrave.
 His superb horsemanship and his recklessness combined to make him a stand-out subaltern, however, and Seydlitz emerged as a redoubtable "Rittmeister" (cavalry captain) in the War of Austrian Succession (1740–1748), also known as the First and Second Silesian Wars.
Frederick II (German: "Friedrich" ; 24 January 171217 August 1786) was King of Prussia from 1740 until 1786, the longest reign of any Hohenzollern king.
 His most significant accomplishments during his reign included his military victories, his reorganization of Prussian armies, his patronage of the arts and the Enlightenment in Prussia, and his final success against great odds in the Seven Years' War.
 Frederick was the last titled King in Prussia and declared himself King of Prussia after achieving full sovereignty for all historical Prussian lands.
 Prussia had greatly increased its territories and became a leading military power in Europe under his rule.
 He became known as Frederick the Great ("Friedrich der Große ") and was affectionately nicknamed "Der Alte Fritz " ("Old Fritz") by the Prussian and later by all German people.
Götz Freiherr von Houwald (May 13, 1913 – August 16, 2001) was a German diplomat, historian and ethnographer.
 He was born in Posen and died in Bonn.
 His full name was Maximilian Otto Gustav Albrecht Hubert Wilhelm Götz-Dieter Freiherr von Houwald.Götz-Dieter von Houwald's parents were Albrecht Freiherr von Houwald und Helene Gräfin von Carmer.