Landgraviate of Hesse-Kassel followed by Electorate of Hesse
End of the landgraviate
Following the reorganization of the German states during the German mediatisation of 1803, the Landgraviate of Hesse-Kassel was raised to the Electorate of Hesse and Landgrave William IX was elevated to Imperial Elector, taking the title William I, Elector of Hesse. The principality thus became known as Kurhessen, although still usually referred to as Hesse-Kassel.
In 1806, William I was dispossessed by Napoleon Bonaparte for his support of the Kingdom of Prussia in the War of the Fourth Coalition. Kassel was designated as the capital of a new Kingdom of Westphalia, where Napoleon appointed his brother Jérôme Bonaparte as king. Following Napoleon's defeat in 1813, the elector was restored. At the Congress of Vienna, a number of Napoleonic electorates were elevated to kingdoms, and William tried to secure recognition as King of the Chatti. However, he was rebuffed by the Great Powers, who listed him as a "Royal Highness" along with the other grand dukes. To secure his pre-eminence over his cousin, the Grand Duke of Hesse in the former Hesse-Darmstadt, William chose to keep his title of Prince-Elector. The rulers of the Electorate of Hesse became the only Prince-Electors in the German Confederation, even though there was no longer a Holy Roman Emperor for them to elect.