Johann Josef Cajetan Graf von Klenau, Freiherr von Janowitz (; 13 April 1758 – 6 October 1819) was a field marshal in the Habsburg army. Klenau, the son of a Bohemian noble, joined the Habsburg military as a teenager and fought in the War of Bavarian Succession against Prussia, Austria's wars with the Ottoman Empire, the French Revolutionary Wars, and the Napoleonic Wars, in which he commanded a corps in several important battles.
In the early years of the French Revolutionary Wars, Klenau distinguished himself at the Wissembourg lines, and led a battle-winning charge at Handschuhsheim in 1795. As commander of the Coalition's left flank in the Adige campaign in northern Italy in 1799, he was instrumental in isolating the French-held fortresses on the Po River by organizing and supporting a peasant uprising in the countryside. Afterward, Klenau became the youngest lieutenant field marshalThe youngest lieutenant field marshal not of the House of Habsburg. At age 20, Archduke Charles, Duke of Teschen, was the youngest. in the history of the Habsburg military.
As a corps commander, Klenau led key elements of the Austrian army in its victory at Aspern-Essling and its defeat at Wagram, where his troops covered the retreat of the main Austrian force. He commanded the IV Corps at the 1813 Battle of Dresden and again at the Battle of Nations at Leipzig, where he prevented the French from outflanking the main Austrian force on the first day of the engagement. After the Battle of Nations, Klenau organized and implemented the successful Dresden blockade and negotiated the French capitulation there. In the 1814–15 campaign, he commanded the Corps Klenau of the Army of Italy. After the war in 1815, Klenau was appointed commanding general in Moravia and Silesia. He died in 1819.
Family and early career
Johann Josef Cajetan von Klenau und Janowitz was born into an old Bohemian nobile family at Benatek Castle(; ) in the Habsburg province of Bohemia on 13 April 1758. The family of Klenau dates to the fifteenth century, and the family of Janowitz to the fourteenth. Friedrich Bernau. Studien und Materialien zur Specialgeschichte und Heimatskunde des deutschen Sprachgebiets in Böhmen und Mähren. Prague: J.G. Calve, 1903, pp. 7–8, 151–165, 601. Other sources date the Klenau family to the early twelfth century. See Norbert (or Enoch) Heermann, Johann Matthäus Klimesch, and Václav Březan. Norbert Heermann's Rosenberg'sche chronik. Prag, Köngl. Böhmische gesellschaft der wissenschaften, 1897, p. 102. The family name of Klenau regularly appears in records after the sixteenth century. The Klenau family was one of the oldest dynasties in Bohemia, and many of the noble families of Bohemia have sprung from marriages into the Klenau line. The original name of the family was Przibik, with the predicate von Klenowa. The family was raised to the baronetcy in 1623 with the certificate granted to one Johann von Klenowa and, in 1629, to his son, Wilhelm. The Imperial councilor and judge in Regensburg, Wilhelm von Klenau, was raised to comital status in 1630, and to the status of Reichsgraf, or imperial count, in 1633.Contemporaries of Johann von Klenau included a cousin, Ignaz, born in Niederösterreich (Lower Austria) who entered the Maria Theresa Military Academy in 1778, was listed in the ranks as a cadet in 1779, and who disappeared from the muster lists in 1795. Johann Svoboda. Die Theresianische Militär-Akademie zu Wiener-Neustad: und ihre Zöglinge von der Gründung der Anstalt bis auf unsere Tage. Wien: Hof- und Staatsdruckerei, 1894–1897, p. 207.
Johann Klenau entered the 47th Infantry Regiment EllrichshausenNote: Austrian regiments often bore the name of prominent Proprietor (Inhaber)s, or sometimes called Colonel-Proprietors, or for notable actions at which the regiment received battle honors. A Colonel-Inhaber/Colonel Proprietor was originally a noble (or wealthy aristocrat) who raised the regiment. Subsequently, a noble or an officer who had achieved some distinction was appointed to the regimental position as an "honorary" appointment. If the appointment was honorary, a "second" colonel was appointed who would fulfill the duties of the colonel. Stephen Herold. The Austrian Army in 1812. In: La Société Napoléonienne. 1996–2003. Retrieved 30 December 2009. in 1774, at the age of 17, and became a second lieutenant in 1775. Jens-Florian Ebert. "General der Kavallerie Graf von Klenau". Die Österreichischen Generäle 1792–1815. Napoleon Online.DE. Retrieved 15 October 2009; Leopold Kudrna and Digby Smith. "Klenau". A biographical dictionary of all Austrian Generals in the French Revolutionary and Napoleonic Wars, 1792–1815. Napoleon Series, Robert Burnham, editor in chief. April 2008 version. Retrieved 19 October 2009. After transferring to a Chevauleger regiment as a Rittmeister, or captain of cavalry, Klenau fought in the short War of the Bavarian Succession, also known as the Potato War. Most of this conflict occurred in Bohemia (part of the modern Czech Republic) from 1778 to 1779, between the Habsburg monarchy, Saxony, Bavaria and Prussia. The war had no battles, but was instead a series of skirmishes and raids, making it the ideal situation for a captain of light cavalry. In their raids, forces from both sides sought to confiscate or destroy the other's provisions, fodder, and materiel.Marshall Dill. Germany: a modern history. Ann Arbor: University of Michigan Press, 1970, p. 52.
In the Austro–Turkish War (1787–1791), one of the House of Habsburg's many 18th-century wars with the Ottoman Empire, Klenau served in the 26th Dragoon Regiment Toscana, and later transferred to the 1st Dragoon Regiment Kaiser. His regiment repulsed an attack of superior numbers of Ottoman forces on 28 September 1788, at Zemun, near Belgrade, for which he received a personal commendation and earned his promotion to major. In his early military career Klenau demonstrated, not only at Zemun but also in the earlier skirmishing and raids of 1778 and 1779, the attributes required of a successful cavalry officer: the military acumen to evaluate a situation, the flexibility to adjust his plans on a moment's notice, and the personal courage to take the same risks he demanded of his men. Jens-Florian Ebert. "General der Kavallerie Graf von Klenau".
French Revolutionary Wars
Background
Initially, the rulers of Europe considered the 1789 revolution in France as an affair between the French king and his subjects, and not a matter in which they should interfere. However, as the rhetoric grew more strident after 1790, the European monarchs began to view the French upheavals with alarm. Among the concerned monarchs were the Holy Roman emperor Leopold II, who feared for the life and well-being of his sister, the queen of France, Marie Antoinette. In August 1791, in consultation with French émigré nobles and Frederick William II of Prussia, he issued the Declaration of Pillnitz, in which they declared the interest of the monarchs of Europe as one with the interests of Louis XVI and his family. They threatened ambiguous, but quite serious, consequences if anything should happen to the royal family.Timothy Blanning. The French Revolutionary Wars. New York: Oxford University Press, 1996, pp. 41–59.
The French Republican position became increasingly difficult. Compounding problems in international relations, French émigrés agitated for support of a counter-revolution.Chief among them were the Prince of Condé, his son, the Duke de Bourbon, and his grandson, the Duke of Enghien. See Blanning, p. 44. From their base in Koblenz, adjacent to the French–German border, they sought direct support for military intervention from the royal houses of Europe, and raised an army. On 20 April 1792, the French National Convention declared war on Austria and its allies. In this War of the First Coalition (1792–1798), France ranged itself against most of the European states sharing land or water borders with her. Portugal and the Ottoman Empire also joined the alliance against France.Blanning, pp. 44–59.
Klenau and the War of the First Coalition On 12 February 1793, Klenau received his promotion to lieutenant colonel in a Lancer regiment, and joined the Austrian force in the Rhineland, serving under General of Cavalry Count Dagobert Sigmund von Wurmser. He was captured later in the spring near the town of Offenbach, but was freed unexpectedly by two Austrian Hussars from the 17th Regiment Archduke Alexander Leopold, who came upon him and his captors. At the first Battle of Wissembourg, Klenau commanded a brigade in Friedrich, Baron von Hotze's 3rd Column on 13 October 1793, during which the Habsburg force stormed the earthen ramparts held by the French.Digby Smith. "Wissembourg." The Napoleonic Wars Data Book. London: Greenhill, 1998, , p. 58.
By the terms of the Peace of Basel (22 July 1795), the Prussian army was to leave the Rhine and Main river valleys; as it did so, the French quickly overran these territories. On 20 September, the fortress at Mannheim surrendered to the French without firing a shot.Wolfgang Menzel. Germany from the Earliest Period. Mrs. George Horrocks, trans. German 4th edition, London: Bohn, 1849, pp. 36–39. Mannheim had been garrisoned by a Bavarian commander, Lieutenant General Baron von Belderbusch, and several battalions of Bavarian grenadiers, fusiliers, and guard regiments, plus six companies of artillery. A small Austrian force augmented the Bavarian contingent. At the same time, further north, the fortified town of Düsseldorf, also garrisoned by Bavarians, capitulated to the French. With these capitulations, the French controlled the Rhine crossings at Düsseldorf and at the junction of the Rhine and the Main rivers. To maintain contact with the forces on their flanks, the Austrian commanders, outraged at this fait accompli, had to withdraw across the Main river.Smith. "Mannheim". Data Book. p. 105.
The nearby city of Heidelberg, further south of the Main on the Neckar River, appeared to be the next French target. Lieutenant Field Marshal Peter Quasdanovich,There are various spellings of his name: Quosdanovich is also a common spelling. Smith, Data Book. p. 105. who had remained in the region between Mannheim and Heidelberg, used a hastily enhanced abatis to establish a defensive line at the sleepy country village of Handschuhsheim, east of the city of Heidelberg. Ursula Perkow, "Der Schlacht bei Handshuhsheim" . KuK Militärgeschichte. Lars-Holger Thümmler, editor. 2009. Retrieved 28 November 2009. The French force of two divisions—about 12,000 men—outnumbered the 8,000 defenders, and the position seemed untenable.
Klenau's charge