Jérôme-Napoléon Bonaparte (15 November 1784 – 24 June 1860) was the youngest brother of Napoleon I and served as Jerome I, King of Westphalia between 1807 and 1813. Napoleon made his brother King of Westphalia, the short-lived realm (1807-1813), created, by Napoleon, from the several states and principalities in northwestern Germany (in the former thousand-year old Holy Roman Empire).
The Napoleonic realm of Westphalia had its capital in Kassel (then: Cassel). As a model state, the Kingdom of Westphalia was expected by Napoleon to serve as an example for the other German states. It received the first constitution and parliament to be found on German soil (decades before other parliaments, legislatures, reichstags, bundesrats, etc. such as in Frankfurt in 1848). Jérôme imported the Empire style from Paris, bestowing the new state with a modern, representative appearance. The small kingdom thus received more attention since the famous “Treaty of Westphalia” which ended the Thirty Years’ War a hundred and fifty years earlier in 1648. Thanks to these efforts by King Jerome, Kassel celebrated an enormous cultural upturn.