After the outbreak of the
War of the First Coalition, Werneck participated in the unsuccessful
Siege of Thionville in September 1792. He served as a brigade commander in the Artillery Reserve under
Olivier, Count of Wallis. Werneck led a contingent of grenadiers with distinction at the
Battle of Jemappes on 6 November 1792. In December 1792,
Pierre de Ruel, marquis de Beurnonville led 20,000 French troops to overrun the
Electorate of Trier. He was opposed by a force commanded by
Friedrich Wilhelm, Fürst zu Hohenlohe-Kirchberg. The defenders were surrounded by 4 December, but thereafter they repelled repeated French attacks. In this stage of the fighting, Werneck commanded the Reserve at
Grevenmacher which included single battalions of the
Matheson Infantry Regiment Nr. 42 and
Murray Infantry Regiment Nr. 55, plus two squadrons of the
Latour Chevau-léger Regiment Nr. 31. By 17 December, the French effort collapsed and Beurnonville's army melted away. Werneck was present at
Aldenhoven on 1 March 1793 where
Henri Christian Michel de Stengel's column was defeated by two Austrian cavalry regiments. He fought in the
Battle of Neerwinden on 18 March. He served at the successful
Siege of Valenciennes from 25 May to 27 July and at the failed
Siege of Dunkirk from 24 August to 8 September. He led a brigade in
József Alvinczi's Reserve at the
Battle of Le Cateau on 29 March 1794. At the
Battle of Tourcoing on 17–18 May 1794, Werneck led a brigade in Column No. 2 under
Rudolf Ritter von Otto. On the first day, only the columns of the
Duke of York and Otto reached their targets. The French counterattack on the second day mauled both columns and forced them to retreat. Promoted to
Feldmarschall-Leutnant on 28 May 1794, Werneck served in the army of
William, Hereditary Prince of Orange. During the
Siege of Nijmegen (27 October–8 November), the Duke of York and
François Sébastien de Croix de Clerfayt tried to work out a plan to drive back the French using Werneck's 7,000 men. However, Nijmegen fell too quickly to the French and Werneck's operation was abandoned. In 1795 Werneck led troops in Clerfayt's army on the middle
Rhine. The actions included the
Battle of Mainz on 29 October, where he led the Reserve, and the
Battle of Pfeddersheim on 10 November. Werneck served in
Archduke Charles, Duke of Teschen's brilliant
Rhine Campaign of 1796. At the
Battle of Würzburg on 3 September 1796, he led a division of 12 grenadier battalions in
Wilhelm von Wartensleben's Reserve. His brigade commanders were
Johann Kollowrat,
Joseph von Schellenberg, and
Ludwig von Vogelsang. On 18 September he was awarded the Commander's Cross of the Military Order of Maria Theresa. When Charles took troops to join
Maximilian Anton Karl, Count Baillet de Latour, Werneck was left in command of the independent
Army of the Lower Rhine beginning in September. His position remained unmolested by the French during the winter. On 18 April 1797,
Lazare Hoche and 38,000 French troops from the
Army of Sambre-et-Meuse caught Werneck's 21,000 Austrians by surprise in the
Battle of Neuwied. After heavy fighting, his soldiers were driven from the field with losses of about 1,000 killed and wounded, plus 3,000 captured. In addition, 24 artillery pieces, 60 wagons, and five colors were captured by the French. Total French losses were 2,000. On 17 April, when
Jean Etienne Championnet's division threatened Werneck's right wing, the Austrian general weakened his left under
Pál Kray in order to bolster his right. When the divisions of
Paul Grenier and
François Joseph Lefebvre began crossing the Rhine at 3:00 AM, Werneck hurriedly ordered Kray's troops back to defend his left. Lefebvre defeated the Austrian left flank, while Grenier broke through Kray's line of redoubts at Heddersdorf after repeated assaults. Hoche's offensive forced the Austrians into a deep withdrawal which ended only with news of the
Treaty of Leoben. After the defeat, Werneck was placed in retirement on half-pay. ==Napoleonic Wars==