The Gąsawa massacre was an attack on the night of 23-24 November 1227, during a council of Polish Piast dukes that was being held near the village of Gąsawa in Kuyavia, Poland. The High Duke of Poland
The Gąsawa Congress, by Matejko. Participants in discussion before the massacre.
Monument at the site of Leszek's death
Death of Leszek the White, by Matejko. Leszek, High Duke of Poland, was caught in his bath but fled on horseback. The attackers caught up with him a few kilometers out of Gąsawa.
Jan Alojzy Matejko was a Polish painter, a leading 19th-century exponent of history painting, known for depicting nodal events from Polish history. His works include large scale oil paintings such as
Matejko, before 1883
Portrait of Matejko's father, Franciszek, and three of his children, 1853, National Museum, Wrocław
Matejko's family home at 41, Floriańska Street
Jan Matejko, Stańczyk, 1862, National Museum in Warsaw