A Napoleonic client state carved from Prussian (and later Austrian, 1809) partition shares of Poland, created by the Treaties of Tilsit as a nominal restoration of Polish statehood under French protection, with the Duke of Warsaw title held by the King of Saxony.
Dissolved after Napoleon's defeat; partitioned at the Congress of Vienna (1815) between Russia (creating Congress Poland), Prussia, and Austria.
Standard single-volume history covering the Napoleonic-era Duchy in context.