The Greater Poland uprising of 1918–1919, or Wielkopolska uprising of
1918–1919 or Posnanian War was a military insurrection of Poles in the
Greater Poland region 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 by the German Kingdom of Prussia.