Marie Casimire Louise de La Grange d’Arquien

Marie Casimire Louise de La Grange d’Arquien, known in Poland as Marysieńka, was a French-born noblewoman who became queen consort of the Polish–Lithuanian Commonwealth through her marriage to John III Sobieski. Brought to Poland as a child in the household of Queen Marie Louise Gonzaga, she first married Jan Sobiepan Zamoyski. After his death she married Sobieski in 1665, years before his election as king in 1674.

The surviving correspondence between Marie Casimire and Sobieski records an unusually well-documented royal marriage as well as the political calculations surrounding it. As queen she participated in patronage, dynastic planning and diplomacy, particularly efforts to strengthen French connections and secure the future of her children. After Sobieski’s death in 1696 she became involved in the disputed succession before eventually leaving the Commonwealth, living for years in Rome and later France, where she died in 1716.

Henryk Sienkiewicz’s On the Field of Glory is the linked novel in which Marie Casimire appears. Set in the political and military world that precedes John Sobieski’s greatest victories, it draws on the courtly networks surrounding the future king and queen, making Marysieńka’s relationship with Sobieski part of the dynastic and factional background of the narrative.