The painting depicts the moment of the vow of faith made to the Blessed Virgin Mary, declared the Queen of Poland, by the then King John Casimir in Lwów (Lviv) cathedral. The ceremony took place on 1 April 1656, and was combined with the royal pledge to further extend the civic rights of the Polish nobility, and to improve the living conditions of the peasantry. The painter showed the historic figures who participated in the event, such as Crown Commander Stefan Czarniecki (with a sabre in his hand) who led the fight against the Swedish invasion, and was actually depicted with Matejko’s own face. The largest oil painting in the Wrocław collection was painted from March to October 1893, but remained unfinished due to the sudden death of the 55-year-old artist.