Against the background of the Northern Seven Years’ War, a Dutch fleet carrying salt from France to the Baltic was arrested in 1564 by the Danish authorities in the Sound, and only allowed to proceed after declaring under oath that they would not sell their cargo to Denmark’s enemy. Afterwards, having reached the Baltic, the fleet encountered a Swedish man-of-war which (according to the Dutchmen) forced them to sail to Stockholm, where the salt was sold at a fixed price. The fleet then sailed to Danzig, where the ships and goods were seized. The incident appears to have played a part in the closure of the Sound to Dutch trade by the Danish Crown, which tried to put pressure on the rulers of the Netherlands for their support in his war efforts. A practical solution to the diplomatic crisis was worked out in setting up a trial opposing the king of Denmark to the skippers of the seized ships before the municipal authorities of Danzig, a city under the overlordship of the King of Poland, who was allied to Denmark in the war against Sweden, while Danzig itself endeavoured to avoid any direct involvement in the warfare. The lawsuit followed the format of civil law procedure. The memorandum and rejoinders, together with a consilium to which a subscriptio by several law professors of Louvain was added, document how a political and diplomatic dispute could be defused and managed through quasi-judicial proceedings and legal arguments. An interim decree of the Danzig authorities discharged the Dutch skippers (1565) and that provisional outcome was eventually confirmed by the king of Poland’s final decision (1567).