Kassel was the capital of the Landgraviate of Hesse-Kassel between 1567 and 1803, the Kingdom of Westphalia between 1807 and 1813 and the Electorate of Hesse until 1866. In 1949 Kassel was also one of the cities seeking to become the provisional capital of the Federal Republic of Germany. The city is known for its palaces and parks.
The Bergpark Wilhelmshöhe was begun in 1689 by Landgrave Carl of Hesse-Kassel and depicts the ideals of absolutist Monarchy and the aesthetics of the Baroque and Romantic periods.
Since 2013 is the Bergpark Wilhelmshöhe on the UNESCO World Heritage List.
The Wilhelmshöhe Castle was built between 1786 and 1798 in the Neoclassical style at the behest of Landgrave Wilhelm IX of Hesse. It was once used as residence of Jérôme Bonaparte, King of Westphalia, after his old residence burned down in 1811. Between September 1870 and March 1871 Napoleon III was held in captivity in the castle.
Today houses the Wilhelmshöhe Castle various museums including the Gallery of the Old Masters.