Question: Ulm Campaign was influential in the development of a plan during which war?
Context: The Schlieffen Plan (German: "Schlieffen-Plan" , ] ) was the name given after World War I to the thinking behind the German invasion of France and Belgium on 4 August 1914.  Field Marshal Alfred von Schlieffen, the Chief of the Imperial Army German General Staff from 1891 to 1906, devised a deployment plan for a war-winning offensive, in a one-front war against the French Third Republic from 1905–06.  After the war, the German official historians of the "Reichsarchiv" and other writers, described the plan as a blueprint for victory.  German historians claimed that the plan had been ruined by "Generaloberst" (Colonel-General) Helmuth von Moltke the Younger, the Commander-in-Chief of the German army after Schlieffen retired in 1906, who was dismissed after the First Battle of the Marne (5–12 September 1914). The Battle of Elchingen, fought on 14 October 1805, saw French forces under Michel Ney rout an Austrian corps led by Johann Sigismund Riesch.  This defeat led to a large part of the Austrian army being invested in the fortress of Ulm by the army of Emperor Napoleon I of France while other formations fled to the east.  Soon afterward, the Austrians trapped in Ulm surrendered and the French mopped up most of the remaining Austrians forces, bringing the Ulm Campaign to a close. The 9th Light Infantry Regiment (9e régiment d’infanterie légère) was a French army regiment.  One of the most notable infantry regiments in the Napoleonic Wars, it was awarded the title "Incomparable" by Napoleon Bonaparte after their brilliant performance at the Battle of Marengo on 14 June 1800.  The regiment went on to serve with distinction in the [Ulm Campaign], at the Battle of Dürenstein (11 November 1805), the Jena Campaign (1806), and the Battle of Friedland (14 June 1807).  The regiment then served in the Peninsular War taking a notable role at the Battle of Talavera 27–28 July 1809 and the Siege of Badajoz (1812).  Battalions from the regiment also fought on the Wagram Campaign (1809), at the Battle of Leipzig (16–19 October 1813), and Napoleon’s campaigns in France (1814).  During the Hundred Days the 9th Light fought at Battle of Ligny (16 June 1815) and the Battle of Wavre (18–19 June 1815).  The regiment was disbanded in the aftermath of the Bourbon Restoration. The Ulm Campaign was a series of French and Bavarian military maneuvers and battles to outflank and capture an Austrian army in 1805 during the War of the Third Coalition.  It took place in the vicinity of and inside the Swabian (then Bavarian) city of Ulm.  The French Grande Armée, led by Napoleon Bonaparte, comprised 210,000 troops organized into seven corps, and hoped to knock out the Austrian army in the Danube before Russian reinforcements could arrive.  Through rapid marching, Napoleon conducted a large wheeling maneuver that captured an Austrian army of 23,000 under General Mack on 20 October at Ulm, bringing the total number of Austrian prisoners in the campaign to 60,000.  The campaign is generally regarded as a strategic masterpiece and was influential in the development of the Schlieffen Plan in the late 19th century. In the Battle of Wertingen (8 October 1805) Imperial French forces led by Marshals Joachim Murat and Jean Lannes attacked a small Austrian corps commanded by Feldmarschall-Leutnant Franz Xaver von Auffenberg.  This action, the first battle of the Ulm Campaign, resulted in a clear French victory.  Wertingen lies 28 km northwest of Augsburg.  The combat was fought during the War of the Third Coalition, part of the Napoleonic Wars. Three ships of the French Navy have borne the name Donawerth, in honour of the battle of Donauwörth during the Ulm Campaign : The Reserve Cavalry Corps or Cavalry Reserve of the "Grande Armée" was the name of a French military formation that existed during the Napoleonic Wars.  In 1805, Emperor Napoleon appointed Marshal Joachim Murat to command all the cavalry divisions that were not directly attached to the Army Corps.  During the Ulm Campaign, Murat led his horsemen in successfully hunting down many Austrian Empire units that escaped the Capitulation of Ulm.  Murat's horsemen fought at Austerlitz in December 1805.  Under Murat, the Cavalry Reserve played a prominent role in the destruction of the Kingdom of Prussia's armies after the Battle of Jena-Auerstadt in 1806.  Five dragoon divisions of the corps were employed in the Peninsular War starting in 1808 and placed under the overall command of Marshal Jean-Baptiste Bessières.  The Cavalry Reserve was reassembled in 1809 to fight Austria with Bessières still in command.  In 1812 the Reserve Cavalry Corps was split up into the I, II, III, and IV Cavalry Corps for the French invasion of Russia. Johann Sigismund Graf von Riesch (2 August 1750 – 2 November 1821) joined the army of Habsburg Austria as a cavalry officer and, during his career, fought against the Kingdom of Prussia, Ottoman Turkey, Revolutionary France, and Napoleon's French Empire.  He became a general officer during the French Revolutionary Wars and held important commands during the War of the Second Coalition.  He displayed a talent for leading cavalry formations, but proved less capable when given corps-sized commands.  During the 1805 Ulm Campaign in the Napoleonic Wars, the French badly defeated his corps and forced it to surrender soon afterward.  From 1806 to his death in 1821, he was the Proprietor (Inhaber) of an Austrian cavalry regiment. The Battle of Ulm on 16–19 October 1805 was a series of skirmishes, at the end of the Ulm Campaign, which allowed Napoleon I to trap an entire Austrian army under the command of Karl Freiherr Mack von Leiberich with minimal losses and to force its surrender near Ulm in the Electorate of Bavaria. The Trachenberg Plan was a campaign plan created by Allied commanders in the 1813 German Campaign during the War of the Sixth Coalition of the Napoleonic Wars, and named for the conference held at the palace of Trachenberg.  The plan advocated avoiding direct engagement with the French emperor, Napoleon I.  This resulted from fear of the Emperor's now legendary prowess in battle.  Consequently, the Allies planned to engage and defeat the French Marshals and Generals separately, and thus weaken his army while they built up an overwhelming force even he could not defeat.  It was decided upon after a series of defeats and near disasters by the Coalition at Napoleon's hands at the battles of Lützen, Bautzen and Dresden.  The plan ultimately worked and at the Battle of Leipzig, where the Allies had a considerable numerical advantage, the Emperor was soundly defeated and driven out of Germany, across the Rhine back into France itself.  The plan was an amalgam of two prior works: The Trachenberg Protocol and the Reichenbach Plan, authored by the Austrian chief of staff of the allied coalition, Radetzky and the Swedish Crown Prince Charles John (formerly Napoleon's marshal Jean Baptiste Bernadotte) whose experience with the tactics and methods of the French Army, as well as personal insight on the mind of Napoleon, proved invaluable.  The combined, modified version of the two prior plans became known as the Trachenberg Plan.
Answer: World War I