Johann, Freiherr von Hiller (1748-1819) was one of the more capable Austrian generals during the Franco-Austrian War of 1809, but his obvious ambition made him unpopular amongst his fellow generals and he missed the decisive battle of Wagram after asking to be relieved from command on grounds of sickness on the day before the battle.
Hiller was a capable general, popular with his own men, and one of the few Austrian generals who was capable of operating without constant supervision from above, but he was also seen as being ambitious and using underhand methods to achieve his aims. The Archduke Charles, brother of the Emperor and commander-in-chief of the army during the 1809 command described him as 'an able man, but of unlimited ambition, which he deviously advanced'.
Hiller was the son of a junior officer in the Sachsen-Hildburghausen regiment, and he joined his father's regiment as a Kadett at the age of 15. Five years later he had reached the rank of unterleutnant, and was transferred to the Württemberg Dragoon regiment. In 1774 he purchased the rank of Hauptmann (captain) in the 5.Warasdin-Kreuz Grenz Regiment (infantry based on the border with the Ottoman Empire). This purchase was apparently somewhat controversial.
Hiller first saw active service in the War of the Bavarian Succession (1777-1779), but he came to prominence during the Turkish War of 1787-1791. He was awarded membership of the Maria Theresa Order in 1788 for his successful defence of part of the frontier with the Ottoman Empire, and was ennobled (becoming Freiherr von Hiller) and promoted to Oberst (colonel) for his part in the capture of Berbir in 1789. He also served as the General Adjutant to the army commander Field Marshal Laudon for some time.
In 1794 Hiller gained promotion to Generalmajor, apparently by dubious means that angered other Austrian generals. In the same year he was given command of a brigade in Italy, but he didn’t impress there, and returned to Germany in 1796. This time he was more successful, although just as his star was rising he was forced to retire due to ill health. He was able to return to duty in 1798, and commanded a division during the fighting in Switzerland in 1799. He was wounded in the leg during the First Battle of Zurich (June 1799) and then acted as liaison officer with the Russians.
In 1800 Hiller was promoted to Feldmarschalleutnant (Lieutenant-General), and in 1801 he was appointed to command the Croatian Districts of the Military Frontier, from a base at Agram (modern Zagreb). His next appointment was as Commandant of the Tyrol, a post that gave him a minor role in the disastrous campaign of 1805. Hiller's task was to defend the southern Tyrol to protect the link between the two main Austrian armies, under Mack and Archduke Charles. After Mack was forced to surrender at Ulm Hiller was forced to retreat each to cover the Archduke John's retreat from the Tyrol.
After the disastrous end of the War of the Third Coalition Hiller was posted to the Croatian General Command, based once again at Agram. He resisted the Archduke Charles's attempts to reform the Austrian army, even going as far as complaining directly to the Emperor Francis, a move that led to poor relations between Hiller and his commander-in-chief during the war of 1809.
Hiller commanded the Austrian VI Korps during the unsuccessful invasion of Bavaria at the start of the Franco-Austrian War of 1809 (War of the Fifth Coalition). As Archduke Charles led his army slowly through Bavaria towards the Danube Hiller's corps was posted to the left wing, facing towards the approaching French and Allied armies, and unknown to the Austrians, the newly arrived Napoleon. On 20 April Napoleon launched his own counterattack (Battle of Abensberg), catching the Austrians by surprise and splitting the Archduke's army in half.
In the aftermath of this battle Hiller found himself in command of the isolated left wing of the Austrian army, consisting of his own IV Korps, V Korps and II Reserve Korps. At first Napoleon believed that this was the main part of the Austrian army, and on 21 April Hiller was forced to fight a second battle, at Landshut. Only after this battle did Napoleon realise that the main Austrian army was actually away to his north, facing a single French corps (Davout). On 22 April Napoleon turned north, inflicting another defeat on Charles at Eggmuhl. Charles was forced to retreat across the Danube at Regensburg, which then fell to the French on 23 April.
Once Hiller knew Charles was across the Danube it was clear that his only option was to retreat east away from Napoleon. Hiller's conduct of this retreat was somewhat variable. He was prone to over-exaggerate the significance of every delay in the French pursuit, misinterpreting halts forced by broken bridges as a significant change of plan. As a result his retreat progressed rather unevenly, and the French were given a number of unexpected chances to catch the retreating Austrians.
Some of Hiller's optimism is perhaps understandable. In the days after the battle of Landshut he only faced a small French force under Marshal Bessières. Hiller was able to retreat safely across the Inn back into Austria, before turning back to inflict a sharp defeat on Bessières at Neumarkt (24 April 1809). Only after this success did Hiller learn of the Austrian defeats and Eggmuhl and Regensburg, forcing him to retreat back behind the Inn.
Over the next two weeks Hiller received a series of orders to cross the Danube and rejoin the main army. The pursuing French, now consisting of the main army under Napoleon, were held up on several occasions by broken bridges, giving Hiller the time he needed to obey those orders, but instead on each occasion he paused, believing that he could make a stand, before suffering another defeat. On 1 May his covering forces were defeated at Riedau, and on 3 May a potentially strong position on the Traun at Ebelsberg was lost to the French.
In the aftermath of this defeat Hiller managed to escape across the River Enns, destroyed the bridges behind him. Once again this gave him the time he needed to obey orders and cross to the north bank of the Danube, but instead he decided to try and defend his new position east of the River Ybbs. Once again the French caught up, winning another victory at Blindenmarkt on 6 May. In the aftermath of this minor defeat Hiller finally obeyed his orders, and moved towards the Danube.
Hiller eventually crossed the Danube on 8 May, but only after sending a significant part of this command straight to Vienna. Once across the river Hiller led the rest of his force east, taking up a position opposite Vienna on the north bank of the Danube. From there he sent part of his force into Vienna, but then received orders not to post any of his men in the city. Once it became clear that the city could not be defended Hiller withdrew those troops already across the river, and the short siege of Vienna (10-13 May 1809) ended in an easy French victory.
Napoleon was now stuck on the south bank of the Danube, with the reunited Austrian army facing him across the river. Napoleon's first serious attempt to cross the Danube ended in his first significant battlefield defeat, at Aspern-Essling (21-22 May 1809). Hiller commanded VI Korps during this battle, and was heavily involved in the vicious fighting in the village of Aspern, which eventually fell to the Austrians towards the end of the two-day battle. Hiller was promoted to the grade of Commander Cross in the Maria Theresa Order and to the rank of Feldzeugmeister (general of infantry) for his part in the battle.
Despite some limitations Hiller's performance during the retreat from Bavaria and at Aspern-Essling showed that he was one of Charles's most capable subordinates, and perhaps the only one capable of operating independently with any chance of success. It was thus unfortunate that Hiller and Charles had a long-running feud dating back to Hiller's opposition to the military reforms.
In the aftermath of Aspern-Essling Hiller was the main advocate of an immediate attack on the isolated French troops on the Lobau, but Charles overruled him. During the two months that separated Aspern-Essling from Wagram (5-6 July 1809) Hiller's anger at the way he though he was being treated built up, until on 4 July he asked to be relieved from command of his corps on the grounds of illness. This request was granted, and VI corps went into the battle under the command of General Klenau. After his recovery from sickness, Hiller returned to his posting in Croatia.
After the Austrian re-entry in the war against Napoleon in 1813 Hiller was appointed to command the Army of Inner Austria, and ordered to attack the French in Italy (commanded by Eugène de Beauharnais, viceroy of Italy). Hiller's initial movements forced Eugène to retreat from Illyria (late September 1813), but Hiller's advance then stalled. In November he was replaced by Bellegarde, who didn't perform much better. Hiller retired from the army in the following year.