This article considers the blocking of the Scheldt River mouth, i.e., the blockade of navigation on the Lower Scheldt between Antwerp and the sea. Organized by the Republic of the United Provinces during the war between the Netherlands and Spain in the late sixteenth century, it continued throughout the entire existence of the Republic. The blockade had a significant impact on the development of the United Provinces’ (first of all, on the province of Zeeland) economy and affected the economy of the Southern Netherlands, mainly Antwerp, becoming one of the reasons for the decline of this once powerful centre of trade. At the turn of the twenty-first century, studying new materials, Dutch and Belgian researchers gradually returned to examining the blockade of the Scheldt, which had not been sufficiently studied so far. As for national historiography, this article is the first attempt at covering this topic. The author briefly outlines the background of the “blockade” of the Scheldt and traces how it was legally formed based on contractual acts of the seventeenth–eighteenth centuries. She describes the purpose of the blockade of the river mouth and the mechanism for regulating navigation in its lower part. The blockade of the Scheldt mouth prevented vessels from freely passing the Lower Scheldt to and from the southern Dutch ports, but this did not mean the blockade of trade. It was about changing its rules: the introduction of mandatory transshipment of goods in the ports of Zeeland from ships of the Southern Netherlands to Dutch lighters that delivered goods along the Scheldt to Antwerp. The Dutch forts of Lillo and Liefkenshoek played an important role in admitting ships to Antwerp and levying taxes for the Republic’s treasury. Using visual material — a map of the first half of the seventeenth century by Willem Blaeu — the article gives an idea of the Scheldt near Antwerp and the South Dutch fortifications located along the banks. ; Целью статьи является рассмотрение проблемы закрытия устья Шельды — блокады ...