Johann Joseph, Prince of Khevenhüller-Metsch (3 July 1706 â 18 April 1776) was an Austrian statesman and held a high position at the imperial court. From 1764 he was the first prince from the House of Khevenhüller.
Khevenhüller was born in Vienna on 3 July 1706. He was the eldest son and heir of Sigmund Friedrich von Khevenhüller and, his second wife, Ernestine Leopoldine von Orsini-Rosenberg.
He received his schooling from a private tutor. He completed humanistic and legal studies in Vienna, Leyden and Strasbourg, and entered the civil service in 1725 as a Lower Austrian regimental councillor after undertaking the "Grand Tour" of Europe.
In 1727, he received the honorary title of Imperial Chamberlain. From 1728 he was an Imperial Court Councillor. Together with his father, he acquired Riegersburg Castle in Hardegg in 1730 and had it converted into a baroque castle by the architect Franz Anton Pilgram. In 1751, he set up a foundation at Riegersburg which financed a pastor for the church in neighbouring Felling. Between 1734 and 1737 he served as an ambassador in Munich, The Hague and Copenhagen. He returned in 1737 and supported his father, who was governor at the time.
In 1740, at the beginning of the reign of Empress Maria Theresa, he was Envoy Extraordinary in Dresden and Warsaw. There he tried to work to maintain peace. After his return to Vienna, he was given various court offices. From 1742 he was Imperial Lord Marshal. In 1745 he was Bohemia's envoy at the imperial election of Francis I in Frankfurt. In the same year, the emperor appointed him Lord Chamberlain. In 1765 he became second Lord Chamberlain and in 1770 first Lord Chamberlain . This was the highest court office. At the same time, he was State and Conference Minister. As such, he exercised considerable political influence.
The hereditary landmaster's office for Carinthia had been in the family since 1568. In 1751, Johann Joseph acquired Ladendorf Castle in Lower Austria. In 1775, he received the vacant office of chief hereditary landmaster of the Archduchy of Austria under the Enns for himself and his descendants.
In 1764, he and his heirs were elevated to the rank of Imperial Prince as majorat owners on the occasion of the coronation of Joseph II as Emperor. He had been a Knight of the Golden Fleece since 1744.
In 1728, Khevenhüller married Karolina Countess von Metsch, heiress of the Imperial Vice-Chancellor () Count Johann Adolf von Metsch, who had died without male issue. Since 1751, he and his descendants called themselves Khevenhüller-Metsch. The couple had several children:
Prince Johann died on 18 April 1776 in Vienna and was succeeded by his eldest son, Johann Sigismund Friedrich.
In 1894, KhevenhüllerstraÃÂe in Vienna-Währing (18th district) was named after him.