Emanuel de Witte. Port Market. Late 1660s.

Emanuel de Witte's painting Port Market depicts a typical market scene in Amsterdam, the main city of Holland—the wealthiest province of the republican Netherlands in the 17th century. The subject of the painting relates to several legal themes, one of which is the legal regulation of ports.
At that time, the right to establish norms belonged not only, or even primarily, to the central authorities of the Netherlands—the States General—but also to individual provinces and the largest municipalities, among which the major port city of Amsterdam held a special place. The regulations adopted there served exclusively local interests and often contradicted the unity of national legislation in the Netherlands.
The municipal government of Amsterdam consisted of a sheriff, four burgomasters, nine aldermen, and thirty-six city councillors, collectively known as regents. Throughout the early modern period, the Amsterdam authorities issued a wide array of ordinances and regulations governing key aspects of urban economic life, including port and shipyard operations, shipbuilding, maritime and inland navigation, as well as warehousing and storage practices. Furthermore, they defined relations between merchants, established rules for retail trade in the port, included provisions for obtaining trade licenses, regulated maritime insurance, and much more.

Another legal theme related to the painting's subject is the regulation of the fisheries. In the 17th century, the Netherlands possessed the largest fishing fleet in Europe, comprising around 2 000 vessels. The economic might of the Dutch provinces was already evident during Spanish rule. Though occupying a small territory within Spain's vast colonial empire—which included extensive dominions in South America—the Netherlands generated nearly half of its revenues.
The Dutch herring industry was particularly renowned. Its regulation began long before the Netherlands gained independence. In 1519, Charles V, Holy Roman Emperor and King of Spain (which then ruled the Netherlands), issued the first comprehensive law governing herring fishing in the Dutch provinces. With minor amendments, this law remained in force until the 19th century. 

The law prohibited the sale of unprocessed herring abroad; all caught fish had to be marked with special identifiers. It also set fixed dates for the start of the fishing season, regulated catch volumes, and established processing and storage standards for herring products.

After gaining independence, the Netherlands established a special collegiate body of cities to oversee the international trade of Dutch herring. Rotterdam and other port cities competing with Amsterdam held dominant positions in this body. Interestingly, representatives from Amsterdam were denied licenses for international trade, limiting the city to coastal herring fishing and supplying only its local urban market.

The rapid expansion of economic ties necessitated new financial instruments for managing credit and cash flows. One such instrument was the "obligatie" (Dutch for "bond") - debt receipts that were used to make payments and secure debts. 
However, during this period, the term "obligatie" encompassed nearly all debt instruments, ranging from private promissory notes to official debt securities issued by city councils.

As fishing and trade required substantial capital and involved significant risks, most merchants couldn't finance their ventures independently. Consequently, fishing enterprises were often established as a legal form of partnerships. Each partner would invest in a vessel's operating costs, typically purchasing shares (e.g., 1/2, 1/4, 1/8), with profits distributed according to share size.

The life of Emanuel de Witte and his family members is well-documented in court records. Notably, his second wife and daughter were convicted of theft. His wife was sentenced to the pillory and six years' banishment from Amsterdam, while his daughter received a one-year sentence in a prison spinning house. De Witte himself also became entangled in legal proceedings. Facing poverty in his final years, he was compelled to live with wealthy citizens  under an obligation to give all newly painted works in return for housing and food. 
This arrangement led to a lawsuit with the widow of one of his patrons, who claimed ownership of paintings that, according to their contract, were to belong first to her late husband before passing to her as inheritance.

Emanuel de Witte was one of the most talented Dutch realist painters. In his works, interiors are depicted on a grand scale, employing complex perspective constructions. De Witte's works are recognizable for their masterful use of linear perspective.