When visiting exhibitions in Swedish museums, especially in Stockholm or Uppsala, one may come across objects of Polish provenance. In many cases these will be military items, but at the National Museum the exhibition of 17th-century art is supplemented by two busts stolen from Warsaw's Kazimierz Palace.

The busts of the royal couple - John Casimir Vasa and Louise Maria Gonzaga - were made by the Roman sculptor Giovanni Francesco de Rossi, known as La Vecchietta (d. after 1680), a pupil of the eminent Italian sculptor Alessandro Algardi. Rossi was brought to the Polish-Lithuanian Commonwealth to complete royal commissions, including the sculptural decoration of the Villa Regia, known as the Casimir Palace, i.e. a private residence located in the then suburbs of Warsaw (the building is now the seat of the Rector's Office of the University of Warsaw on the main campus) at Krakowskie Przedmieście Street. Between 1651 and 1655, the sculptor also completed commissions for other commissions, including a bust of Piotr Gembicki, Bishop of Krakow.

The accounts of the royal court of 8 October 1651 record payment to the artist for the making of a marble bust of the king and two clay models, one of which probably depicted Ludwika Maria: "To the Italian stonemason Skulptor for a stone conterfekt of HM the King and two clay pieces fl. 300" (Tomkiewicz 1957). These works were probably made outside Warsaw, as evidenced by another note stating that the sculptor received additional payment for their transport to the city: "Temuż on the way to Warsaw fl. 150. facit fl. 450" (Tomkiewicz 1957). It is most likely that they were made in Gdansk, where John Casimir stayed in the early autumn of 1651. Rossi made his works from the most expensive and finest Carrara marbles, also used in Rome, and so from 'marmo bianco statuario'. They are each 62 cm high, with overall dimensions of 121.5 x 34 x 31 cm (John Casimir) and 122 x 34 x 32 cm (Louisa Maria). They are also signed by the sculptor: GIO: FRAco: ROSSI (king) and G-Fco ROSSI (queen).

John Casimir is depicted in plate armour, tied with a sash, with the Order of the Golden Fleece hanging from a chain. On his head he is wearing a wig 'à la lion', referring to Hondius' engraving and Schultz's lost portrait. The face has been depicted realistically, with visible wrinkles, leading us to suspect that the bust may have been created 'ad vivum'. Louise Marie is depicted in a gown with a deep neckline, held up by a brooch of three pearls, a recurring motif in depictions of the queen, as is her smoothly combed hair with curls falling to her shoulders. Rossi omitted the string of pearls encircling the Queen's neck in other depictions.

The sculptures adorned the royal private residence, the Villa Regia (Casimir Palace). The busts were looted by the Swedish army during the Swedish 'deluge' and transported to Sweden. They were initially taken to the Stockholm Royal Castle, as appears to be evidenced by a register of objects looted from the Commonwealth in 1656. The register in question is an inventory of items taken out of Warsaw is kept at Slottsarkivet in Stockholm in the group 'Inventarium öfwer Huusgerådz Cammaren pro Anno 1655'. It is in the form of a six-page manuscript, prepared in Old Swedish, sewn into a book collecting 17th- and 18th-century inventories of Stockholm Royal Castle. The inventory was prepared by the Swedish royal administration and the items transported were taken to Stockholm Royal Castle during the 'Flood'. The two sculptures of the 'King and Queen of Poland in alabaster' are an interesting item. The descriptions contained in the source are often enigmatic and do not always allow for the identification of the listed objects, but in this case it seems likely, although confirmation of this fact requires in-depth archival research, that these may be busts of Ludwika Maria and Jan II Casimir.

In 1953, the sculptures were donated to Gripsholm Castle. They are now on display in the permanent exhibition of the National Museum in Stockholm in room 1613, where 17th-century art is shown.