Strait cash: Iran revives a centuries-old maritime business model

Strait cash: Iran revives a centuries-old maritime business model
Andrew Craig-Bennett May 20, 2026 https://splash247.com/strait-cash-iran-revives-a-centuries-old-maritime-...

Andrew Craig-Bennett on what Iran can learn from the kings who monetised the Baltic.

“History doesn’t repeat itself, but it often rhymes” Mark Twain

The Strait of Hormuz has been pretty much closed for more than 80 days now. Iran wants to control the strait and charge a toll. The US doesn’t want them to. Everyone else is fed up but – oh, what lovely freight rates – if you can earn them!

I thought it might be fun to look back to an earlier episode of charging for passage through a strait of great economic importance.

I refer to the Sound Dues, the Oresundstolden, which were first charged, on all ships and cargoes passing into or out of the Baltic, by King Erik VII of Pomerania, in 1429, and which were charged by, at various times, the Kalmar Union (that’s Denmark, Sweden and Norway together) Sweden and Denmark and latterly by the Kingdom of Denmark, until 1857, when the most important cross trading shipowning nation of the day, the United States, refused to pay them, and they were abolished in return for one time payments from all the important flag states of 1857 except Brazil, which didn’t pay up, and was finally let off in 2007, when Ander Fogh Rasmussen told Ignacio da Silva (in the course of a state visit) that Brazil was excused.

The history of the Sound Dues is very long, very complicated, and rather bloody, with one war after another fought over them, and for a couple of hundred years they provided about two-thirds of the income of the Kingdom of Denmark. We can see that the Islamic Republic of Iran is onto a nice little earner, here.

King Erik VII was one of those monstrous figures, like King Gustavus Adolphus of Sweden, Peter the Great of Russia and his arch enemy King Charles the Twelfth of Sweden, that Northern European history throws up from time to time. Handsome, intelligent, charming, and, alas, pig headed. He got his throne because his great aunt adopted him, married King Henry the Fifth of England’s sister, went on pilgrimage to Jerusalem, started the Sound Dues and was eventually sacked by the Danes, who got tired of him starting wars for no good reason and not finishing them properly.

It seems clear that King Erik’s cunning plan occurred to him because cannon had developed to the point where guns mounted in fortresses either side of the narrows could reliably hit any ship passing between them, and (history rhymes!) the herring fishery in the sound, which had been huge, was falling off because of over fishing, so he needed a new source of income.

The master stroke was to levy the toll at 1% of the value of the cargo and – this is the clever bit – to ask the master to state the value of his cargo, with the Danish government having the option of buying in the cargo at that figure.

At one point the Kingdom of Denmark charged the English Muscovy Company dues for taking the long way round and reaching Russia via the North Cape – more rhyming history!

More elaborate dues, such as light dues, were added as time went on, and arrangements for charging ships in ballast were included.

In the end it all got too complicated, with ships being held up whilst the Danish customs people tried to find out the values of things that they had never heard of, and then the Americans, who really were the Greeks of the day, with a huge fleet of cross traders, built with all that softwood from their forests, got fed up and refused to pay. They could have asked for Greenland, of course, but they had no use for it, then.

So there you have it. I offer this cunning plan from 1429, free of charge, to the governments of Iran, Oman, Indonesia, Malaysia and Singapore, just pausing to point out that valuing ships and cargoes is much easier now, with VesselsValue and electronic manifests, and so is collecting the loot.

The US doesn’t have the ships, now, so they don’t really care.