After Napoleon imposed the Convention of Artlenburg (Convention of the Elbe) on July 5, 1803, about 30,000 French soldiers occupied Hanover. The Convention also required disbanding the army of Hanover. However, George III did not recognize the Convention of the Elbe. This resulted in a great number of soldiers from Hanover eventually emigrating to Great Britain, where the King's German Legion was formed. It was the only German army to fight against France throughout the entire Napoleonic wars. The Legion later played an important role in the Battle of Waterloo in 1815. The Congress of Vienna in 1815 elevated the electorate to the Kingdom of Hanover. The capital town Hanover expanded to the western bank of the Leine and since then has grown considerably.