Born in Brussels, he succeeded his father as ruler of Württemberg at the age of 9, but the real power was in the hands of AdministratorsCarl Rudolf, Duke of Württemberg-Neuenstadt and Carl Frederick von Württemberg-Oels. He was educated at the court of Frederick II of Prussia. In the Seven Years' War against Prussia, Charles Eugene advanced into Saxony. He ruled until his death in 1793, when he was succeeded by his younger brother. He was an early patron of Friedrich Schiller. He also studied keyboard with Carl Philipp Emanuel Bach in the 1740s. In 1761, Charles Eugen founded an Académie des Arts in Stuttgart, in 1765 a public library in Ludwigsburg, and he was responsible for the construction of a number of other key palaces and buildings in the area including the New Palace which still stands at the centre of the Schlossplatz, Castle Solitude and Castle Hohenheim. Charles Eugene married twice, first in Bayreuth on 26 September 1748 to Margravine Elisabeth Fredericka Sophie of Brandenburg-Bayreuth with whom he had one daughter, Friederike Wilhelmine Augusta Luise Charlotte, who was born in Stuttgart on 19 February 1750 and died after 13 months in Stuttgart on 12 March 1751. Elisabetha left Charles Eugene in 1756 to return to her parents' court in Bayreuth although they never divorced. In the meantime, Charles Eugene kept a string of mistresses and fathered eleven children by them. The last of these mistresses was Franziska von Hohenheim, whom he raised to the status of Countess and married in Stuttgart on 10 or 11 January 1785. Charles Eugene was known for his interest in agriculture and travel and is considered the inspiration behind today's Hohenheim university. His original botanical gardens form the basis for today's Landesarboretum Baden-Württemberg and Botanischer Garten der Universität Hohenheim, which still contain some of the specimens he planted. He also built a large number of palaces and bankrupted his lands through courtly extravagance, accepting huge French government loans in exchange for maintaining large numbers of support troops in Württemberg. In his early years he ruled with an iron fist. However, he also displayed humanist tendencies. For example, in 1744 he ordered that the corpse of Joseph Süß Oppenheimer – the executed Jewish financial advisor of his father, Charles Alexander – whose decaying corpse had been suspended in an iron cage by Stuttgart's Prag gallows for six years – be taken down and given a decent burial. He was also well known for his extensive library, his extravagant interest in opera, and interest in large scale horticulture for the feeding of the masses. Between 1751 and 1759 Karl Eugen was involved in an increasingly bitter struggle with his adviser, the eminent Liberal jurist Johann Jakob Moser who strongly opposed the Duke's absolutist tendencies. In 1759 Charles Eugene had Moser charged with authoring "a subversive writing" and cast into prison for the next five years. However, in 1764 Moser was released, due in part to the intercession of Friedrich the Great of Prussia, and was rehabilitated and restored to his position, rank and titles. Charles Eugene died in Hohenheim. Charles Eugene made the first of his five trips to Paris and the Palace of Versailles in 1748 with his first wife. He used these trips to sightsee and acquire Parisian goods for Ludwigsburg Palace while touring the workshops those goods were manufactured in. From 1776 Etienne Sollicoffre, a banker Charles Eugene had met in Paris, befriended the Duke and acted as the agent of his purchases in the city.
Karl=David von Franquemont, married firstly in May 1795 to a Freiin von Hügel, by whom he had a daughter, and married secondly in May 1795 to Luise Sophie Henriette von Jett, by whom he had a daughter:
* Charlotte Elisabeth Piron von Franquemont, who lived in Ceylon and married Hendrik Rademaker, without issue
* Karoline Luise von Franquemont, married on 21 October 1819 Johann von Raben, without issue
By Regina Monti he had:
Friedrich, Graf von Franquemont, unmarried and without issue, general and War minister.