On 27 December in 1918 the Wielkopolska uprising (Greater Poland Uprising of 1918–1919 or Posnanian War ) started. It was a military insurrection of Poles in the Greater Poland region (German: Grand Duchy of Poznań or Provinz Posen) against German rule. The uprising had a significant effect on the Treaty of Versailles, which granted a reconstituted Second Polish Republic the area won by the Polish insurrectionists. The region was part of the Polish-Lithuanian Commonwealth before the Second Partition of Poland in 1793 when it was taken over the German Kingdom of Prussia.
The uprising was caused by the arrival in Poznan of the internationally acclaimed composer and pianist Ignacy Paderewski who delivered a speech that stirred pro-independent demonstrations in the city. The uprising spread to many cities and towns in the region of Wielkopolska; the insurgents were able to achieve many of their military and political objectives. The fighting ended on 16 February 1919. The success of the insurgency and the liberation of Wielkopolska from Prussian rule had a significant impact on international peace negotiations, and the final shape of the Versailles Treaty.
Source: Poland.pl, Wikipedia
Photo: Wikimedia Commons