Franz von Rottenburg was born in Danzig, Kingdom of Prussia4 November 1757, son of Franz Gottlieb von Rottenburg and Anna Maria Brunati. He served in the French army, under the name de Rottenburg rather than von Rottenburg, from March 1782 to September 1791, his service ending during the early years of the French Revolution, then returning to Danzig and commanding a battalion of infantry in Tadeusz Kościuszko’s uprising. In December 1795, de Rottenburg joined the British army, serving in Hompesch's Hussars, a unit of foreign-born troops. In 1796 he helped to establish Hompesch's Light Infantry, which later became part of the 5th Battalion of the 60th Regiment of Foot. This battalion was formed mainly from German émigrés. De Rottenburg rose to the rank of lieutenant-colonel in the unit, and commanded it during the Irish Rebellion of 1798 and the capture of Suriname in 1799. De Rottenburg wrote a series of manuals which became the basis for the training of riflemen and light infantry under Sir John Moore. He later commanded a brigade of light troops in the Walcheren Campaign.
De Rottenburg was promoted to Major General on the staff in British North America and arrived in Canada in 1810. When the War of 1812 with the United States broke out, he assumed command of the Montreal district. He assumed responsibility for both the civil and military leadership of Lower Canada on two occasions during the absence of Sir George Prevost, the commander in chief. In 1813, he succeeded Major General Sir Roger Hale Sheaffe as military and civil commander in Upper Canada. He was accused of neglecting civil duties and of being unduly cautious in his military decisions. He refused to send reinforcements to Major General Henry Procter, commanding on the Detroit frontier, and this ultimately led to the British defeats at the Battle of Lake Erie and the Battle of Moraviantown. He later imposed martial law in the Eastern and Johnstown districts to force farmers to sell supplies to the army, an unpopular move which his successor repealed but was nevertheless forced to reimpose upon all of Upper Canada. In December 1813, de Rottenburg was succeeded by Lieutenant GeneralSir Gordon Drummond, and returned to his previous posts in Lower Canada. Later in 1814, substantial British reinforcements arrived in Canada. Sir George Prevost prepared to invade the United States by way of Lake Champlain. He placed de Rottenburg in command of a division of three brigades. However, Prevost personally led the campaign, which was defeated at the Battle of Plattsburgh. Prevost, de Rottenburg and their staffs were criticised by the three brigade commanders, all of whom had seen much action in the Peninsular War, for their lack of fortitude at Plattsburgh.
Later life
De Rottenburg was recalled to Britain in December 1814 and left Quebec in July 1815. He was appointed Knight Commander of the Royal Hanoverian Order in 1817 and Knight Bachelor on 12 February 1818. He was promoted to Lieutenant General on 12 August 1819. He died in Portsmouth on 24 April 1832.
Family
De Rottenburg had married Juliana Wilhelmina Carolina von Orelli, the daughter of Johann Ulrich von Orelli, a Neapolitan general, in Bratislava on 4 January 1802. They had one son and one daughter. Son George Frederick de Rottenburg was a British Army officer who arrived in Canada in 1830s and was militia officer in Upper Canada. Rottenburg left Canada in 1852.
