Landgraviate of Hesse-Kassel - Aftermath

Aftermath

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, and Kassel became the capital of a new Kingdom of Westphalia with Napoleon's brother Jérôme Bonaparte as king. The elector was restored following Napoleon's defeat in 1813, and although the Holy Roman Empire was now defunct, William retained his title of Elector, as it gave him pre-eminence over his cousin, the Grand Duke of Hesse. From 1813 onwards, the Electorate of Hesse was an independent country and, after 1815, a member of the German Confederation.

William's grandson, Elector Frederick William, sided with the Austrian Empire in the Austro-Prussian War, and after the Prussian victory his lands were annexed by Prussia in 1866. Along with the annexed Duchy of Nassau and Free City of Frankfurt, Hesse-Kassel became part of the new Province of Hesse-Nassau of the Kingdom of Prussia.

In 1918, Hesse-Nassau became part of the Free State of Prussia until 1944. From 1944–45 as part of Nazi Germany, it was divided into the Prussian provinces of Kurhessen and Nassau. From 1945–46, it was renamed Greater Hesse (German: Großhessen) and was part of the US occupation zone in Germany. From 1946 onwards, it was reorganised into the State of Hesse, a federal state of West Germany.

In 1918, Prince Frederick Charles of Hesse, younger brother of the head of the house and a brother-in-law of Emperor William II, was elected by the pro-German Finnish government to be King of Finland, but he never reigned.

In 1968, the head of the House of Hesse-Kassel became the head of the entire House of Hesse due to the extinction of the House of Hesse-Darmstadt.