Gąsawa massacre

'Gąsawa crime') was an attack on the night of 23 / 24 November 1227 during a council of Polish Piast dukes which was being held near the village of Gąsawa in Kuyavia, Poland.

[4] Świętopełk's aim was to make the Duchy of Gdańsk Pomerania, which his House of Sobiesław held as regents of the Polish rulers, independent of Piast overlordship.

A particularly puzzling fact is the absence of condemnation by ecclesiastical authorities (some of whom were present at the meeting), who at that time took an active role in Polish political affairs and tended to react strongly to regicides.

[6] Whatever the exact circumstances of, or the responsibility for, the event, it is generally accepted that the crime contributed to the deepening of the feudal fragmentation of Poland.

Poland, as a unified political entity, would not be re-established until the reign of Wenceslaus III or Władysław the Elbow-high at the turn of the 13th and 14th centuries.