# Could a medieval fantasy world sustain itself by occupying important trade hubs and taxing trade?

The civilization I'm talking about is marked in pink (cities A and B).

The trade routes are marked in yellow.

Owning the city B (the entire island) means they only need to travel across two relatively small gaps by sea, unlike other civilizations, in case they decided to get rid of the middle-man.

Could this advantage be enough to sustain cities without proper farms? (instead the food would be bought from their neighbors).

• From ancient times to today, bulk transportation on water has been much cheaper than land transportation. Bulk transportation includes foodstuffs. Ancient examples include the logistics of Alexander the Great's campaigns; modern examples include barges on the Mississippi River and its tributaries. Does your world have major differences from ours, to suppress bulk water transport or encourage land transport? – Jasper Feb 23 at 12:20
• @Jasper Actually I thought about it almost immediately after posting the question and started googling. It just seemed intuitive to me that having an ability to rest and resupply would make a lot of sense and until I wrote it down it never bothered me. Luckily being a fantasy world i'm free to throw in fictional reasons for this to work like sea-monsters making it dangerous to sail in big open areas of water. Thanks a lot for pointing it out. – MadCake Feb 23 at 12:30
• @MadCake, you can even have real world reasons to prevent sailing in open areas of water: navigation. IRL for ages ships only sailed along the coast (or between coasts close to each other), because if they would lose sight of the dryland they most likely would be lost in the sea. And maybe even die there, most likely of thirst and starvation, or scruvy. – user28434 Feb 23 at 17:51
• @user28434 Thanks for the idea. Loosing sight of the dryland makes sense but I'm confused about thirst/starvation/etc after Jasper's comment. Did they actually stop to resupply regularly? – MadCake Feb 23 at 21:58
• @MadCake, even you have some water and sea rations stored on board, your sailors will always appreciate fresh water and food from the land. Because stored supllies will get worse in quality everyday, and sea ration had infamously bad taste and quality. Btw, history stackexchange has relevant question. – user28434 Feb 24 at 22:12

A real-world, real-history example:

## The Sound Dues

The Sound, known by the natives as the Øresund [ˈøːɐsɔnˀ], is one of three natural waterways connecting the Baltic Sea with the ocean; the other two are the Great Belt and Little Belt. Of the three, the Sound is the most convenient for traffic, so that it was a very busy waterway since times immemorial. In the Late Middle Ages and the Early Modern period, the strait was controlled by Denmark; nowadays, the western shore belongs to Denmark and the eastern shore to Sweden.

The Baltic straits. West to east, the Little Belt, the Great Belt, and the Sound. Map by Ulamm, available on Wikimedia under the CC BY-SA 3.0 Unported license.

Political control of Øresund has been an important issue in Danish and Swedish history. Denmark maintained military control with the coastal fortress of Kronborg at Elsinore on the west side and Kärnan at Helsingborg on the east, until the eastern shore was ceded to Sweden in 1658, based on the Treaty of Roskilde. Both fortresses are located where the strait is 4 kilometres wide.

In 1429, King Eric of Pomerania introduced the Sound Dues which remained in effect for more than four centuries, until 1857. Transitory dues on the use of waterways, roads, bridges and crossings were then an accepted way of taxing which could constitute a great part of a state's income. The Strait Dues remained the most important source of income for the Danish Crown for several centuries, thus making Danish kings relatively independent of Denmark's Privy Council and aristocracy. (Wikipedia, s.v. Øresund)

The Sound Dues (or Sound Toll; Danish: Øresundstolden) was a toll on the use of the Øresund which constituted up to two thirds of Denmark's state income in the 16th and 17th centuries.

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. If a ship refused to stop, cannons in both Helsingør and Helsingborg could open fire and sink it. In 1567, the toll was changed into a 1–2% tax on the cargo value, providing three times more revenue. To keep the captains from understating the value of the cargo on which the tax was computed, the elegant solution was chosen to reserve the right to purchase the cargo at the value stated. (Wikipedia, s.v. Sound Dues)

• I love that solution to captains understating their value. It's amazing. – Andon Feb 23 at 17:08
• @Andon I wish we had that solution to excessive property taxes. Make the government offer to buy the property at the amount they say its value is. That'll make 'em stop overpricing it. – Gryphon - Reinstate Monica Feb 23 at 19:16
• @Gryphon I'm with you on that one. I just finished my tax-declaration for 2018. My house would struggle to get sold for €225.000 but for my property tax it is valued at €400.000 by the city council. If they will pay me that they can have it yesterday. – Tonny Feb 23 at 19:52

City states at a 'change of transport' point or cross roads may be able to do this. Whole nations? I doubt it.

I can't come up with a pre-industrial city that was unable to raise essential food in the local neighbourhood.

Rome, after the established an empire, transported grain in by the boatload. But that was just Rome the city. That wasn't true of the countryside around Rome.

Might check out the history of Damascus and possibly other cities on the Silk Road.

In times of prosperity and while they're at peace with their neighbours such a solution might work, if there was enough traffic to tax and enough food was available. But if their neighbours harvests were poor then buying in food would become impossible long before the neighbours were starving. Furthermore any political dispute that led to even a short cessation in trade would be disastrous for any nation without independent means.