Born in Weißenfels in the Electorate of Saxony in 1735, Otto joined the Saxon army in 1753 as a cavalryman. In the Seven Years' War he fought at the battles of Kolín and the Breslau in 1757. He was also present at several sieges and skirmishes. He joined an AustrianFreikorps raised by his brother Wilhelm and participated in several successful ambushes and raids in 1760-1762.
Austrian service
At the end of the war he formally entered the Austrian army, joining the Hesse-Darmstadt Dragoon Regiment # 19 as an Oberleutnant. Promoted to captain in 1769 and major in 1777, he transferred to the Graeven Hussar Regiment # 34. Because he improved his new regiment's efficiency, he was rapidly promoted, first to Oberstleutnant in 1783 and Oberst in 1784. In the Austro-Turkish War, he led his regiment in action at Chernivtsi and Cornia. Promoted to General-major in 1788, he continued to distinguish himself against the Turks. In 1793 during the War of the First Coalition, Otto joined the Austrian army in Flanders, serving at the siege ofValenciennes. At the battle of Caesar's Camp onAugust 7, he commanded an infantry-cavalry brigade in the Count of Clerfayt's column. On September 12, he participated in the cavalry action at Avesnes-le-Sec in which a French force was cut to pieces. On October 30, he led his troops in battle at Marchiennes. He was promoted to Feldmarschal-Leutnant on January 1, 1794 and also became proprietor of the Hussar Regiment # 32. On April 24, while leading two Austrian and two British cavalry squadrons on a reconnaissance toward Cambrai, Otto encountered a force of French cavalry. At this time, he discovered that Emperor Francis II was nearby with his retinue. Fearing that his sovereign was about to be captured, he resolved to attack the enemy. In the ensuing Battle of Villers-en-Cauchies, Otto's troopers smashed a 7,000-man French division, inflicting 1,200 casualties. Two days later, Otto led the main attack in the Duke of York's victory at Beaumont, rolling up the French flank and capturing the French commander René Chapuis. At the Battle of Tourcoing, he led one of York's three columns. Though the Anglo-Austrian army went down to defeat, Otto performed well.
Later career
In 1796, Otto declined a command in Italy due to ill-health. He became a member of the Aulic Council and was promoted to full general upon retirement in 1803. He died at his estate near Königgrätz on August 7, 1811.
