The Austrian army entered the Duchy of Warsaw in 1809. Their scope of operations was to take both sides of the Vistula. Most Polish detachments were in the centre of the Duchy of Warsaw or outside the country, under the direct command of Napoleon. The isolated battalions that remained were in no position to oppose the army approaching from the south. Meanwhile, Archduke Ferdinand, after taking Warsaw, proceeded to the Vistula crossing and gradually occupied the territories along the Prussian border, especially in the Department of Bydgoszcz. It was a similar story in the south of Wielkopolska, where the Austrians were steadily controlling more territory.

It was right then that an uprising against the Austrians was proclaimed on the left bank of the Vistula and the appeal went out for Polish detachments to form. Gen. Jan Henryk Dąbrowski successfully led the campaign in Poznań. Fighting broke out with skirmishes at Słupca and Węgierki (Września County). The Austrians were forced to retreat to Galicia on learning that Prince Józef Poniatowski was advancing. The invading forces were systematically driven out of Wielkopolska and then the entire Grand Duchy of Warsaw. This was the second successful armed Wielkopolska uprising, after the one in 1806-1807.