Nicolaes Tulp attended by prominent learned men, who exchanged ideas about anatomy and the chemical processes of the human body. As befits a new praelector, the Guild commissioned a new group portrait of the prominent councilmen and guildmasters. Rembrandt, himself a young man of 26 and new to the city, won this commission and made a famous painting of him: "The Anatomy Lesson of Dr Nicolaes Tulp". This painting, which now hangs in the Mauritshuis museum of the Hague, depicts Tulp dissecting such a criminal's forearm. There has been much speculation as to why the dissection began on the forearm. Rembrandt's event
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