Schultz became the leading artist at the Warsaw court of the Polish kings in the second half of the 17th century. In 1649 he became a private painter to the Polish king John II Casimir Vasa, and then to successor kings Michael Wiśniowiecki and John III Sobieski. Schultz returned to his hometown around 1660, yet from time to time worked on royal commissions in Warsaw, often in the Wilanów Palace. His great portraits of Polish kings and nobles are among the best examples of Baroque art in Poland. The most notable of his works "Crimean Falconer of King John II Casimir with his Family " (also known as "The Family Portrait", today in the State Hermitage Museum in St. Petersburg) was painted in 1664. It depicts Crimean Agha Dedesh (or Dedis) with his sons and servants. The eldest son of Agha was entitled "Royal Falconer" in reward for his father's support during the Polish war with Russia (1654–1667). This work was painted during Agha's visit to Warsaw after successful invasion of the Left-bank Ukraine (1663–1664). Rich color variations of cerise, dark green and orange create an ideal composition with silver-brown tone of the painting. Some of the portraits of John II are also well known - "en pied" propaganda portrait in Polish costume, when he was leading the Berestechko expedition and so-called "Bielany portrait" in armour with black glow of burning Kraków in background.