Michael Freiherr von Colli-Marchini (1738-1808) was an Austrian general best known for his unsuccessful period in command of the army of Sardinia (Piedmont) during Napoleon's first campaign in Italy in 1796.
Colli was born in Vigevano (Lombary) in 1738. His father was an Italian civil servant in the service of the Austrians and who had been made a baron. Colli chose a different career path, joining the Imperial and Royal Army when he was eighteen. For the first part of his career he served with Infantry Regiment Pallavicini (IR 15), fighting in the Seven Years' War and rising to the rank of captain. He was promoted to lieutenant colonel in 1768, and led an infantry battalion during the War of the Bavarian Succession (1778-1779). In 1779 he was promoted to colonel. He was next promoted during the Austro-Turkish War (1787-1791), rising to major general after playing a prominent part in the siege of Belgrade.
In 1792 the emperor lent Colli's services to Victor Amadeus, king of Savoy (Sardinia and Piedmont). Savoy was one of the first victims of French aggression after the revolution. Nice and Savoy, on the French side of the Alps, were both vulnerable to attack, and were quickly seized by the French. Colli performed well in the campaign in Nice in 1793, but the front line soon ran along the Alps and the Ligurian Apennines.
In 1795 Colli's Piedmontese troops cooperated with Field-Marshal de Vins's Austrian army in an offensive along the Ligurian coast that began well, but ended with a defeat at Loano (23 November 1795) that saw the French capture most of the coast.
It was this French victory that gave Napoleon the base he needed for his successful offensive into Italy in 1796. At the start of the campaign of 1796 Colli's Piedmontese army was based in the south west of Piedmont, watching the southern passes across the Maritime Alps and the route across the Apennines via Ceva. The Austrian army, under Field Marshal Beaulieu, was based further east, around Alessandria. Between then the Allies outnumbered the French, but Colli's army was at best the same size as Napoleon's.
Napoleon took advantage of this separation to launch an attack into the gap between the two armies. Beaulieu was defeated at Montenotte (12 April 1796) and at Dego (14-15 April 1796) and was forced to retreat north-east to protect his lines of communication, which stretched east across Italy towards Austria. This left Colli's Piedmontese vulnerable to a concentrated French attack. Colli's one remaining advantage was his possession of strong defensive positions at Ceva and Mondovi, where mountain ridges effectively blocked the Tanaro valley, Napoleon's best route into southern Piedmont.
On 16 April the French attacked the lines at Ceva and were repulsed, but Colli had already decided to pull back to his next line, along the River Corsaglia. Once again the first French attack on this line was repulsed, but on the night of 20-21 April Colli attempted to retreat to Mondovi. The French caught up with his army before the retreat was complete and inflicted a heavy defeat on it (battle of Mondovi, 19-21 April 1796).
In the aftermath of this defeat the Piedmontese capital at Turin was exposed to French attack. On 23 April Colli asked for an armistice, but Napoleon continued to advance until he had captured Cherasco. On 28 April Napoleon forced the Piedmontese to agree to the Armistice of Cherasco. The French took a number of border fortifications, and were free to turn east to face the Austrians.
Colli returned to Austrian service, where he played a part in the defence of the Mincio River (battle of Borgetto, 30 May 1796). In late January 1797 he was appointed commander in chief of the army of the Papal States, but before he reached the front his army had been defeated by Napoleon and Victor (battle of Faenza, 4 February 1797).
Colli remained in the Austrian army until the Peace of Campo Formio. He then joined the Neapolitan Army, then commanded by another ex-Austrian commander, the unfortunate General Mack. By the start of 1799 Naples too had fallen to the French, and Colli moved on to Florence. His final post was as Austrian ambassador to the king of Etruria (a kingdom created from Tuscany in 1801 under the terms of the Treaty of Lunéville). Colli died in Florence on 22 December 1808.