There is an empire expanding from the Netherlands to Western Russia, the empire is enthusiatic about turning rivers into canals for transportation.

They don't care about the environment, they just need the closest thing to a railway to transport goods and soldiers around. Assuming 14th century technology and "limitless resources" how would they go about connecting, say, the Rhine to the Danube? What about the Elbe, Oder and the Vistula to the Danube? Also, what about Neman, Daugava, Volga and the Dnieper, maybe the Don too.

I know that connecting the Rhine and the Danube is possible since it has been done today, though not directly, and I'm fine with that if it makes possible to connect Germanic and Slavic territories. And more than that I do like to know how it would be done (but please explain it in layman's words).

If it's not possible, maybe because some rivers come from the Alps and other from the Carpathian Mountains or something of that nature, do elaborate on it, I do love to read about it.

Also bonus points if you can say something about the feasibility of such empire, maintaining control of such vast lands through the fast movement of troops through man-made canals.

  • $\begingroup$ I will read the question, so far reacting just on the title: Search for Suez Canal, that has been built in far past $\endgroup$ Jul 4, 2018 at 12:10
  • $\begingroup$ I have read about the Suez and the Panama canal (not that in depth) and i think its not realy what i'm going for...You will understand after reading the question . $\endgroup$
    – Flarion
    Jul 4, 2018 at 12:14
  • $\begingroup$ An empire is feasible in any period with any technology...but an empire is not about 'moving troops quickly' (that's a 19th century strategy). An enduring empire is about harnessing the politics and social structures to accomplish the emperor's goals. Military strategy grows out of smart politics, not the other way around. $\endgroup$
    – user535733
    Jul 4, 2018 at 12:27
  • $\begingroup$ Related: Europe Canal Map. If you haven't moved the mountains or rivers, your empire's canals are likely to follow rather similar paths. $\endgroup$
    – user535733
    Jul 4, 2018 at 12:30
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    $\begingroup$ You're only talking an area about three times the size of Texas. Medieval, bronze age, and even Neolithic societies would be able to do this if it suited their needs and budgets. Even excavating canal routes through mountains would be feasible - check out some of the bronze age excavations in the Middle East. $\endgroup$
    – pojo-guy
    Jul 4, 2018 at 12:38

7 Answers 7


You need a few things to build a canal:

  1. locks, as in locks for ships, not the thing that closes doors. These were first built around the described time, so those are no problem.
  2. the ability to move massive amounts of soil. Surprisingly, it was only recently that man-with-bucket stopped being the most efficient alternative.

A famous example is the White Sea - Baltic canal, built using Gulag labour in the 50s. This was a labour force of 100.000 so those are the numbers you'd be looking for. Note that by medieval standards that is a ludicrous number of people. And assumes that the soil-removal teams can keep up because mining rails won't be invented for another couple hundred years. But a canal like that, through the lowlands, is fairly easy business. The maximum height they reach is 103 meters, the rhine-danube canal is quite a bit higher at 170 metres elevation level. The Russians also made good use of lakes while the Germans had no such luxury.

Also look at the Corinth Canal, several empires including the Romans attempted them but it was only finished in the 1890s.

But for the best example by far look at the Fossa Carolina, a canal built in 793 under orders of an actual emperor. 2km long and a 100m wide linking tributaries of the Danube and Rhine. It is unknown if it was ever finished but the fact that this is debatable indicates that it is not a stupid idea.

So, is it possible: well..it is not impossible. But what you describe is going to be a ludicrously expensive effort in both manpower and materiel. Constructing all the cathedrals in Europe will look like peanuts in comparison. Canals are famous for bankrupting anything who even plans to start one and even a single one of the canals you named could bankrupt your empire.

But a few canals in specific locations that can assist you in logistics? yeah, sure.

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    $\begingroup$ My god the white sea canal is huge! No wonder it took so much to build it. I think I'll base my Rhine-Danube canal on the Fossa Carolina, Thank you very much! I still wonder how to connect the other three nearby rivers... Or if it's even possible. $\endgroup$
    – Flarion
    Jul 4, 2018 at 13:52
  • $\begingroup$ Totally realistic. European empires had never been very efficient, but medieval chinese or ancien egypt empire had several time 100k people working on a single project. $\endgroup$
    – Madlozoz
    Jul 4, 2018 at 14:19
  • $\begingroup$ True, a differently structured society could support a roaming labour force of 100k. $\endgroup$
    – Borgh
    Jul 4, 2018 at 14:29
  • $\begingroup$ Late medieval technology had one huge canal building bonus that nobody mentioned - black powder. $\endgroup$
    – Vashu
    Jul 5, 2018 at 3:28

Romans were not so fond of connecting rivers, but they were great road builders, to move their troops and goods around the empire.

They were pretty straightforward on this: if they wanted to go from A to B and there was a mountain in between, they cut through the mountain when it was possible.

Their cutting technique involved fire and vinegar: light a fire on the rocks, cool them down with water and vinegar, remove the enbrittled rocks.

By using this method the Romans were able to connect Rome to all the cities of their empire, crossing Alps and Apennines, therefore in principle if you have large mass of workers, fire and vinegar you could be able to replicate the process.

The only problem when dealing with rivers is that water, as opposed to horses and walkers, cannot go uphill on its own.

You would need a system of locks to cover the height differences, and maybe use ground transport on certain sections.

Therefore the answer to your question is: yes, it could be possible, having the knowledge of Roman engineering and a large workforce. Also, build ships suited for shallow water, like the Viking drakkars. It will save digging effort.

  • $\begingroup$ That's extremely helpful! I was wondering how the english builded the Glastonbury Canal through a mountain, maybe they did something similar. I dont think locks would be a problem since they where created in this time periode ( and also i have some creative liberty). Also i was thinking on making it a danish empire. i wonder how good where the viking ships at transporting goods. $\endgroup$
    – Flarion
    Jul 4, 2018 at 13:40
  • $\begingroup$ Also, we know that the Romans had relevant engineering expertise, since they used them to build aquaducts. The longest, to Carthage in Tunisia, was 90-132 km long depending on whether you include the side channels. $\endgroup$ Jul 4, 2018 at 13:48
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    $\begingroup$ @Flarion, many of the canal projects were massively over budget and overdue $\endgroup$
    – Separatrix
    Jul 4, 2018 at 13:49
  • $\begingroup$ @Flarion The vinegar and fire was only used by Hannibal once. And it only works on limestone (calcium carbonate). The Romans actually digged mountains with pick and shovel and adding bricks to build a tunnel. $\endgroup$ Jul 4, 2018 at 17:05

I note that boats on rivers and canals can vary in size, and are often quite small. Even ocean going ships could be very, very tiny a few centuries ago.

The Popham Colony in modern Maine built a 30 ton pinnace, the Virginia, in 1607-1608. The 46 colonists abandoned the colony in October 1608 and sailed back across the Atlantic in the terrifyingly small Virginia. Virginia made a round trip across the Atlantic in 1609 as part of the "Third Supply" fleet to Jamestown, and sailed to Virginia again in 1610.


The English ship Squirrel of only 10 tons made at least two transatlantic voyages in the 1570s and 1580s before disappearing on the 3rd voyage in 1583.


in Canada, the Red River Expedition of 1870 had to transport a thousand men, and supplies including cannons, hundreds of miles through a wilderness. Part of the trip was made in many canoes, which were portaged between various watersheds.

In the 17th century the English colonists in Maryland around the Chesapeake Bay and the Dutch colonists around the Delaware Bay carried on illegal trading and so couldn't sail by sea from bay to bay. So ships with their cargoes sailed up creeks from one bay as far as they could, and then were put into giant oxcarts and hauled for miles to the headwaters of creeks emptying into the other bay.

Some of those ships were only for coastal voyages but others were capable of transatlantic voyages.

The great city of Constantinople, "The City of the World's Desire", had a massive iron chain that was used to close off the Golden Horn from enemy ships during attack. A Russian chronicle claims that attacking Russian vikings in 907 hauled their small ships on land, attached wheels, and pulled them overland to enter the Golden Horn despite the chain, but Byzantine chronicles don't mention that attack.



And viking raiders and traders often carried boats and/or ships overland from one river system to another.

And the Ottomans did more ships overland into the Golden Horn during the seige of 1453.


And then there is the Diolkos the pathway, sort of an early railroad, to carry ships across the Isthmus of Corinth during Classical times.


Building canals to connect rivers to avoid portages is a good idea, but not totally necessary.

In 793 Charlemagne tried to dig a two kilometer long canal, the Fossa Carolina, from Truechtlingen to Weissenburg, connected the Schwabian Rezat river to the Altmuhl river, and thus the Rhine-Main and Danube watersheds. This may have been for commercial and/or military purposes. It is unknown whether this canal was completed and operational, but it was the inspiration for modern canals connecting the Rhine and Danube watersheds.


From what I've read, there were a number of vast earth moving projects in Europe in ancient and medieval times, including the Antoine Wall, Offa's Dyke, the Dannewerk, and the Great Fence of Bulgaria.

So building a Rhine-Main-Danube canal would not be totally out of scale in a medieval Europe.

With a medieval Rhine-Main-Danube canal one could sail and row and be towed from the Netherlands to the mouth of the Danube and sail across the Black Sea, and maybe travel up the rivers into Russia.

The Sea of Azov empties into the Black Sea, and the Don River empties into the Sea of Axov. The 101 kilometer long Volga-Don Canal connects the Don River with the mighty Volga River that empties into the Caspian Sea. The Volga River and its tributaries are connected by canals to the Baltic Sea and the White Sea.

I know that in modern Europe there are canals connecting the Rhone and Mediterranean with the Rhine, the Rhine with the Elbe, the Elbe with the Oder, the Oder with the Vistula, the Vistula with the Neman, and the Bug (tributary to the Vistula) with the Dneiper River that flows into the Black Sea. But some of those canals have locks and other modern technology that might be difficult to duplicate with medieval technology.

Another important modern European canal is the 98 kilometer long Kiel Canal across the Jutland Peninsula, allowing ships to sail from the North Sea to the Baltic Sea without having to sail around Jutland. A medieval version of the Kiel Canal could be used for civilian or military transport from the Atlantic Ocean and the North Sea to the Baltic sea.

So it would certainly be possible for a fictional state in medieval Europe to construct canals to make transportation in an east-west direction faster, easier, and cheaper for commercial and/or military reasons.

Canal construction is usually beneficial to society, but construction of the Grand Canal of China was considered a heavy burden by the perhaps short sighted peasants and was one cause for the rebellions that overthrew the Sui Dynasty.


Sorry, but there is a first problem here: There is no such thing as 'limitless resources'. Even if two empires joined forces, they'd have to spend immense fortunes in this massive engineering job, which would be generational in terms of time.

Now, of course no emperor would dare to put a temporal limit to the future of its reign...and that is why he needs advisors, especially on the spending part. And the creation of this water network would divert uncountable numbers of precious manwork from military, farms, everything. And even if they wanted to use armies of slaves, they'd have to divert resources just to take them, move them, feed them and control them.

'Limitless resources' is akin to magic, not a realistic prospective. And the tragic irony is that, as technolgy advances, they'll discover that the canal idea wasn't really that necessary. Roads do just fine, they are cheaper to build, and can be adapted with time as the number and type of vehicles change, while a canal can offer only a limited space, it can accommodate only a few type of ships, and even less in case of draught, or the traffic could be blocked during a flash flood, while a wagon can leave the road and find shelter by a hostel built along the way. So, an empire should improve the road network. Romans created the best European empire around their roads. Sure, the Mediterranean Basin was a precious strategic waterway, but not so when you have to move inland inside the continent.

The reason Holland and Venice could realize their undisputed canal networks is that they are built on the right kind of ground. With a relatively lesser effort, they just had to let the water flow in the direction they needed rather than forcing it into a direction.

Without a heavy machinery industry to help them, your empire cannot do that job in a reasonable time and without draining all of its money.

  • $\begingroup$ I used 'limitless resources' so you didn't have to focus on it and could help me with some cool engineering... The roman empire was based on the italy and the mediterranium, my empire is based in germany, western russia and the inbetween, not having a gigantic lake to connect it i through it would be cool to use the existing river system since it run through all of it. $\endgroup$
    – Flarion
    Jul 4, 2018 at 12:54
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    $\begingroup$ Medieval technology means one thing only: dig! dig dig dig dig and nothing else, with horses and oxen and carts to aid you. Mind me, I did not flat out say it would be impossible, only that it is not worth it, given the purpose. Digging canals it's easy, but on this monumental level this better be the one-thousand year empire and that your neighbors will leave you alone generation after generation. You just can't speed up such an effort $\endgroup$ Jul 4, 2018 at 13:01
  • $\begingroup$ I don't know it dind't strike me as such monumental task. Like Pavel Janicek point out in the other comments the english build a cannal through (kinda of) a mountain in the 10th century just to transport stone to build a abey! Having a connecting between the north sea and the black sea is huge and not nearly that hard (i think). Granted the other projects i mention would be much more dificult but i realy just want to see how far can i push it with a empire crazy for cannals and making rivers navigable, and also i do like to know how they would do it. $\endgroup$
    – Flarion
    Jul 4, 2018 at 13:25
  • $\begingroup$ "And the tragic irony is that, as technolgy advances, they'll discover that the canal idea wasn't really that necessary. " While technically not Medieval the Don and Volga was connected as early as 1569. There was a relatively short distance between them and both rivers have large basins. In XVII c. the German great rivers were connected (long before unification) etc. I think to effectively compete with water for massive good transport you need to progress to at least railway (but you discover that most population centers were next to rivers anyways). $\endgroup$ Jul 4, 2018 at 20:26
  • $\begingroup$ "Romans created the best European empire around their roads." - for army yes but the Mediterranean was the main place of trade. [It's still monumental effort and easily could collapse due to over-investment but as far as transportation and trade goes river and canals are quite sound for the period]. $\endgroup$ Jul 4, 2018 at 20:36

An example of pre-industrial revolution canal is Canal du Midi, a 240km canal finished in 1681.
It took around 15 years with 12k workers using pickaxes and shovels, so nothing new compared to what you would use in the late middle ages.

Estimated cost is around 20M livres. I could not find accurate numbers for this period, but a 100 years later (in French), crown revenues were around 500M a year, with national GDP at ~5/6B livres. GDP was apparently about 4B around 1700, so royal revenues around 300M sound reasonable.
Basically, such a project is expensive, but not stupidly expensive. As a comparison, France involvement in the American war of independence is estimated at around 1B livres.

As people said building the canal itself would not need anything too complicated: locks and lots of people.
However, if you have to crest an elevation to reach the other, then where the water comes from becomes an issue and you can't use the water of one to go into the other. You need to find a source near that summit with enough water to fill your canal in both directions. Or you need to bring that water from somewhere, e.g. using aqueducs. Romans could do it, but it's expensive/time consuming.

Lastly, I think you need to consider maintenance.
Canals tend to silt up really quickly because of the slow moving water, and the whole structure is much more exposed to things like frost, floods, draughts, ...

But nothing impossible if a centralised government puts its mind to it.


It can be done, it have been done, it's being done.

You're asking about Europe and you've read about Panama and Suez. What about, you know, Europe. Here, a map of water transportation in Europe, http://fracademic.com/dic.nsf/frwiki/1471773 there are connections from Rotterdam to Constantinople, from France to Belarus. From Black sea to Baltic. From Baltic to White Sea.

There's a hill on your way? Too tiddly bad we don't care Elbląg Canal

You have place without water but you want to connect it to river? Here, we have 48km long canal that connect Gliwice to Oder. You want to transport that coal to Berlin? No problem, around 1605 they've build Finowkanal, THE OLDEST existing artificial water road. It connect Oder with Havel.

It can be done with shovels, a lot of workers and water gates. That's all. Just dig, build a gate, dig again, build another gate and you're done.

Do empires move people with this method? No, because it's too slow. It's good for moving stuff because you need two maybe three people for one barge and we know we send transportations in middle ages from Pinsk to Odessa that way. And with from Cracow to Kaunas through Vistula, Baltics Sea and Nemunas. People can move much faster than water and can traverse mountains in the shortest distance not the most optimal one as rivers do.

Feasibility of such empire - Roman Empire stretched from Britain through France, Spain, All Medditerean Basin and Black Sea through Armenia to Caspian Sea. There is no reason a smallish empire from Netherlands couldn't reach Belarus, Lithuania or even Moscow.

Prussia stretched from Netherlands to Konigsberg. So exactly to western Russia.


Humans can do a hell of a lot with pick and shovel, if they have enough time and resources so canals could pretty much be cut anywhere you like as long as you have good locks or other water retention technologies.

I would however suggest that canals are not altogether necessary. Have a look at how far the Vikings spread East and South; they often took their longboats over land using portages similar feats of overland boating were undertaken by the Voyageurs on untamed rivers in the Americas. Building good roads that can be used to portage ships and cargo around obstructions both on and between river might be quicker and cheaper.


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