Following French Emperor Napoleon I's victory at the Battle of Jena and the ensuing evacuation by Prussia of her Polish provinces, in November 1806 Poniatowski was asked by the Prussian king Frederick William III to assume the governorship of Warsaw, to which he agreed; he also assumed the command of the city's municipal guard and citizen militia forces organized by local residents. All of this turned out to be a short-lived Polish provisional authority, because quick succession of events on the European scene presented the Poles with new opportunities and forced upon them new choices.