Portrait painting benefitted greatly from such commissions and from the general appreciation of art by bourgeois clients, who supported portraiture as well as still-life and landscapes painting. In addition, the first significant art and dealer markets flourished in Holland at that time. With plenty of demand, Rembrandt was able to experiment with unconventional composition and technique, such as chiaroscuro. He demonstrated these innovations, pioneered by Italian masters such as Caravaggio, most notably in his famous "Night Watch" (1642). "The Anatomy Lesson of Dr. Tulp" (1632) is another fine example of Rembrandt's mastery of the group painting, in which he bathes the corpse
Nicolaes Tulp of his books, Tulp became Mayor of Amsterdam in 1654, a position he held for four terms. His son Dirck married Anna Burgh, the daughter of Albert Burgh, another Mayor of Amsterdam who had, like Tulp, studied medicine in Leiden in 1614. In 1655 Tulp's daughter Margaretha married Jan Six, whom he helped become a Magistrate of family affairs in Amsterdam. Years later, Six would also become Mayor of Amsterdam. Tulp, impressed by his behaviour, invited Paulus Potter to come to Amsterdam, after a quarrel in the Hague. In 1673 Tulp was admitted to the Governing Committee of the Republic