Duchy of Warsaw
The Duchy of Warsaw (Polish: Księstwo Warszawskie; French: Duché de Varsovie; German: Herzogtum Warschau) was a French client state established by Napoleon Bonaparte in 1807, during the Napoleonic Wars. It initially comprised the ethnically Polish lands ceded to France by Prussia under the terms of the Treaties of Tilsit, and was augmented in 1809 with territory ceded by Austria in the Treaty of Schönbrunn.