The ‘massacre’ at Thorn, a small town in Royal (Polish) Prussia, occurred after an incident in July 1724. On 16 July, Thorn's catholics held a procession. Protestants alleged that Lutheran students who refused to bow before the host were forced to do so by students from the Jesuit Gymnasium. The catholics maintained that a Lutheran student had not removed his hat and had mocked the host. A scuffle ensued. Civil order broke down and prisoners were taken by both sides – catholics were dragged to the town hall and protestants to the Jesuit Gymnasium. A protestant mob stormed the Gymnasium to free the Lutheran students. The catholics alleged that statues of the Virgin and other relics had been burned in the street. The mayor eventually called out the militia to calm the situation.

Thorn's Jesuits claimed the city authorities had failed to dispatch the militia quickly enough to quell the riot and had encouraged damage to catholic property. The Sejm, to whom the Jesuits complained, agreed and sentenced several men (including the mayor and his deputy) to death. The catholics were given the last remaining protestant church in Thorn and large fines were imposed upon the town. News of the sentence was treated with incredulity in protestant Europe. Incredulity quickly turned to anger when the executions were carried out on 7 December. The mayor was beheaded privately before dawn and other prisoners were executed publicly shortly afterwards, although the mayor's deputy was pardoned. The precise number originally condemned and eventually executed is disputed. However, the numbers involved (less than fifteen) suggest that to describe it as a ‘massacre’ (or a Blutbad or Blutgericht in German) is something to be explained, rather than assumed.

Within British historiography, Thorn appears as a partial explanation for continuing domestic antipathy to catholics. Older German historiography saw the events at Thorn as symbolic of a wider conflict between the civilised Germans and the barbarian Poles. Few have considered why Britons were interested in the ‘massacre’ or who was directing the diplomatic campaign against Augustus the Strong, the Polish king. This chapter shows how religious tensions were inextricably bound to political disputes in the Empire prior to George I's death in 1727. The use made of the ‘massacre’ in the protestant press reveals much about the protestant cultural assumptions and worldview. The Thorn incident exacerbated tensions between George I and Charles VI.