After the fall of the Duchy of Warsaw, which existed as a Napoleonic client state between 1807 and 1815, and its short-lived "Sejm" of the Duchy of Warsaw, the "Sejm" of Congress Poland was established in Congress Poland of the Russian Empire; it was composed of the king (the Russian emperor), the upper house (Senate), and the lower house (Chamber of Deputies). Overall, during the period from 1795 until the re-establishment of Poland's sovereignty in 1918, little power was actually held by any Polish legislative body and the occupying powers of Russia, Prussia (later united Germany) and Austria propagated legislation for their own respective formerly-Polish territories at a national level.