The history of Kynzvart starts in the latter half of the 13th century. At that time, the Czech King Premysl Otakar II ordered here the erection of a borderland castle, called Kunigeswart, ruins of which can still be seen atop the steep rock above the township of Lazne Kynzvart. In the course of 340 years up to the Thirty Years' War, the castle experienced a rapid succession of 29 owners, descending from ten noble families (in particular, lords of Kynzvart, Osek, Plauen, Svamberk, Pluhs of Rabstejn, and lords of Cedvice and Libstejn).
A Renaissance keep was erected below Kynzvart by the lords of Cedvice in the late 16th century. In 1623, after the Battle of White Mountain, the confiscated demesne of Kynzvart, along with the castle and the Renaissance keep, was taken over by Johann Reinhard and his brothers William, Charles, Emmerich and Lothar - officers of General Wallenstein's army and nephews of Lothar Metternich, Archbishop and Elector of Trier. Then, the Metternichs kept the domain of Kynzvart until its confiscation in 1945. Between 1681 and 1691, Count Philipp Emmerich ordered the replacement of the dilapidated Renaissance keep with a Baroque mansion.
Klement Wenceslas Lothar Johann Nepomuk, the second Prince of Metternich - Winneburg, was born on 15 May 1773 in the Palatine-Rhenish town of Coblenz.
He served as Austria's envoy to Dresden, Berlin and Paris. Between 1809 and 1848 he occupied the post of Austria's Minister of Foreign Affairs. In addition, he became the State Chancellor of Austria in 1821. In 1813 he was elevated to hereditary princedom. Convened under his auspices upon the defeat of Napoleon, the Congress of Vienna (1814 - 1815) addressed international relations by ushering in a system of treaties between the major powers.
Between 1820 and 1833 Pietro Nobile conducted the remodelling of the castle in the style of Viennese Classicism.
At the outset of the revolution in March 1848 and after having handed in his resignation, the Chancellor left for London to live there in voluntarily exile. Following his return three years later, he frequently stayed at Kynzvart until his death on 11 June 1859.