The Grand Duchy of Berg was a short-lived state in the early 19th century, established in 1806 during the Napoleonic Wars. It was located in what is now western Germany and was part of the Confederation of the Rhine, a group of client states under French influence. The capital was the city of Düsseldorf, which served as a cultural and administrative center. The Grand Duchy was ruled by Joseph Napoleon, the brother of French Emperor Napoleon Bonaparte. It existed until 1813, when it was dissolved following the defeat of Napoleon and the subsequent reorganization of Europe at the Congress of Vienna.