Wilhelm (6 July 17852 July 1823) Due to mental illness, Wilhelm was duke in name only, with his cousin Peter, Prince-Bishop of Lübeck, acting as regent throughout his entire reign.
7âÂÂ9 July â The Treaties of Tilsit are signed between France, Prussia and Russia. Napoleon and Russian Emperor Alexander I ally together against the British. The Prussians are forced to cede more than half their territory, which is formed into the Duchy of Warsaw in their former Polish lands, and the Kingdom of Westphalia in western Germany. The Free City of Danzig is also formed (established 9 September by Napoleon).