Sound Dues

The dues were introduced by King Eric of Pomerania in 1429 and remained in effect until the Copenhagen Convention of 1857 (with the sole exception of Swedish ships between 1660 and 1712).

[1] All foreign ships passing through the strait, whether en route to or from Denmark or not, had to stop in Helsingør and pay a toll to the Danish Crown.

In 1658, Denmark-Norway had to cede her provinces east of the sound (Scania, Halland, Blekinge, Bohuslän, and the island of Ven) to Sweden as a consequence of the Second Northern War.

The exemption was withdrawn after Sweden's defeat in the Great Northern War and the Treaty of Frederiksborg of 1720, although the eastern shore of the Sound was now Swedish.

the Sound[2] The Copenhagen Convention,[3] which came into force on 14 March 1857,[4] abolished the dues and all Danish straits were made international waterways free to all commercial shipping.