He was the third but second surviving son of Ernst, Duke of Saxe-Hildburghausen and Sophie of Waldeck-Pyrmont, daughter of German Field MarshalPrince Georg Friedrich of Waldeck. His mother died ten days after his birth, on 15 October 1702. He received the typical education of a nobleman of his time, with some educational journeys to the different countries of Europe. When he was sixteen years old, the prince joined the Habsburg Army and became already in 1719 a Staff Captain in the Infantry Regiment N°18 "Seckendorff", and fought in it in Sicily during the War of the Quadruple Alliance. After his conversion to Catholicism in 1728, began for Joseph a fast ascent in his military career. In 1729 he was appointed lieutenant-colonel and the next year colonel of the Regiment "Palffy". In January 1732 he even got his own 8th Infantry Regiment. Briefly after the outbreak of War of the Polish Succession he served in the following campaigns in northern Italy. He distinguished himself, especially in the Battle of San Pietro, where he was wounded in the face, and was promoted to Lieutenant field marshal before the end of the war. Joseph ended the War of the Polish Succession with the rank of Feldzeugmeister. Only one year later, during the Austro-Turkish War, 1737-1739, he was entrusted with the command of an Austrian Corps. In 1737, his attempt to conquer Banja Luka failed, but in practically all important engagements of the war, Joseph displayed personal bravery, for example in the Battle of Grocka, where he covered the retreat of the Imperial Army.
In the following years, he lived quietly in the Archduchy of Austria. After the outbreak of the Seven Years' War, in the spring of 1757, Joseph was appointed Commander of the Imperial Army, with orders to advance against King Frederick II of Prussia. Together with a French Corps, the Imperial Army was defeated in the Battle of Rossbach. Joseph, shamed by the defeat, decided to renounce all military functions. In the evaluation by later historians the prince was nearly always blamed for the defeat, although he could hardly have changed the outcome of the fight, because of the catastrophic condition of the Imperial Army and the ineffectiveness of the French troops. Rather symbolic was the appointment to the post of Field Marshal of the Imperial Army, with which the military career of Joseph ended. He died shortly after.
Personal life
Joseph maintained for most of his life very good relations with the Habsburg family. In 1739 the Emperor Charles VI appointed him Knight of the Order of the Golden Fleece, the dynastic order of the Habsburgs. On 13 March 1741 he represented King August III of Poland as godfather of the young Archduke Joseph, the son of the Empress Maria Theresa. This illustrates how close he stood to the new Empress, whose close friend he was to remain the rest of his life. On 17 April 1738 Joseph married in Paris to Princess Maria Anna Victoria of Savoy, niece and sole heiress of the enormous fortune of the deceased Prince Eugene of Savoy. She was also twenty years older than he was. Thanks to this union, Joseph came into the possession of large estates and assets. The marriage, however, was unhappy, and in 1752 they separated, but never formalised the divorce. The prince earned himself a reputation as a patron, but also as a spendthrift. He spent most time at his castle in Vienna, but when his relatives the Dukes of Saxe-Hildburghausen were heavily indebted, he became by order of the Holy Roman Emperor Joseph II in 1769 manager of the Duchy, in order to avoid the bankruptcy of Saxe-Hildburghausen. His grandnephew, Duke Ernst Frederick III, was incapacitated to rule. When he died he left a young heir, the seventeen years old prince Frederick, over whom Joseph took on the role of prince-regent, which he retained until his own death, aged eighty-four.
