Finnish peasant Lalli kills English clergyman Henry, the Bishop of Turku, on the ice of Lake Köyliö.

Lalli is an apocryphal character from Finnish history. According to the legend, he killed Bishop Henry on the ice of Köyliönjärvi on 20 January 1156.

Henry was a medieval English clergyman. He came to Sweden with Cardinal Nicholas Breakspeare in 1153 and was most likely designated to be the new Archbishop of Uppsala, but the independent church province of Sweden could only be established in 1164 after the civil war, and Henry would have been sent to organize the Church in Finland, where Christians had already existed for two centuries.

The Archdiocese of Turku, historically known as Archdiocese of Åbo, is the seat of the Archbishop of Turku. It is a part of the Evangelical Lutheran Church of Finland, and its see city is Turku.

Köyliönjärvi is a lake in the municipality of Köyliö, Finland. Lake Köyliö and its surroundings are classified as one of the National landscapes of Finland. The area has been inhabited continuously since the Iron Age.

January 20 is the 20th day of the year in the Gregorian calendar; 345 days remain until the end of the year.