Born in 1696 at Prague, Josef Wenzel was the eldest son of Prince Philipp Erasmus of Liechtenstein (11 September 1664 – 13 January 1704) and Countess Christina Theresa von Löwenstein-Wertheim-Rochefort (12 October 1665 – 14 April 1730). He was a great-grandnephew of Karl, the first Prince of Liechtenstein. In 1712, he succeeded his distant cousin Hans-Adam I, as the Prince of Liechtenstein, even though he was not next in line. The actual heir was his uncle Anton Florian, he was not very popular among the family. Hans-Adam therefore chose Josef Wenzel as his heir, but in 1718 he negotiated with Anton Florian and later swapped the County of Vaduz and the Lordship of Schellenberg in exchange for the Dominion of Rumburk. He also married Anton Florian's daughter Anna Maria Antonie, who was Wenzel's cousin. A year later the two dominions were united into the new Principality of Liechtenstein. He then enjoyed a long life of military successes. Wenzel was primarily a general and was a very successful campaigner. His first venture was in 1717, when he fought against the Ottoman Turks in the Austro-Turkish War, alongside famed military commander Prince Eugene of Savoy. He also participated in the War of Polish succession, once again alongside Prince Eugene. In 1745, he was made Generalissimo in Italy and was victorious the following year at the Battle of Piacenza. In 1753 he was made General Chief Commander in Hungary. In one of the greatest achievements of his career, he reorganised the Habsburg artillery, partially financed out of his own pocket. He was the 698th Knight of the Order of the Golden Fleece in Austria. From 1735 to 1736, he was Imperial Envoy to Berlin and he was Ambassador to Paris between 1738 and 1741. In 1760, he escorted the future bride of Josef II to Vienna.