Åbo Bloodbath: Fourteen noblemen who opposed Duke Charles are decapitated in the Old Great Square of Turku (Swedish: Åbo) for their involvement in the War against Sigismund.

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.

Charles IX, also Carl, reigned as King of Sweden from 1604 until his death. He was the youngest son of King Gustav I and of his second wife, Margaret Leijonhufvud, the brother of King Eric XIV and of King John III, and the uncle of Sigismund, who became king both of Sweden and of Poland. By his father's will Charles received, by way of appanage, the Duchy of Södermanland, which included the provinces of Närke and Värmland; but he did not come into actual possession of them till after the fall of Eric and the succession to the throne of John in 1569.

The Old Great Square is a medieval market square located in the city centre of Turku, Finland. It is located in the II District in very close proximity to Turku Cathedral. The area was the administrative and commercial centre of Turku since the founding of the city in the 13th century up until the Great Fire of Turku.

Turku is a city in Finland and the regional capital of Southwest Finland. It is located on the southwestern coast of the country at the mouth of the River Aura. The population of Turku is approximately 207,000, while the metropolitan area has a population of approximately 317,000. It is the 6th most populous municipality in Finland, and the third most populous urban area in the country after Helsinki and Tampere.