At the culmination of a Swedish civil war, supporters of the deposed King Sigismund III Vasa were publicly executed in the Åbo Bloodbath.

Sigismund III Vasa was King of Poland and Grand Duke of Lithuania from 1587 to 1632 and, as Sigismund, King of Sweden from 1592 to 1599. He was the first Polish sovereign from the House of Vasa. Religiously zealous, he imposed Catholicism across the vast realm, and his crusades against neighbouring states marked Poland's largest territorial expansion. As an enlightened despot, he presided over an era of prosperity and achievement, further distinguished by the transfer of the country's capital from Kraków to Warsaw.

The Åbo Bloodbath of 10 November 1599 was a public execution in the town of Turku (Åbo), Finland, then part of the Kingdom of Sweden, in the context of the war against Sigismund. Sweden was by then in the final phase of a civil war, with one faction supporting King Sigismund III Vasa, who also was King and Grand Duke of Poland–Lithuania, and another faction supporting Duke Charles of Södermanland, the later Charles IX, Sigismund's paternal uncle. After winning the upper hand in the dispute, Charles crushed the last resistance to his rule, particularly in Finland, while Sigismund had already retreated to Poland.