Could Augustus have had a canal built across the Suez? Should he have?

[Threviel]

Yes, and the over-stretch was already visible under Augustus. A Roman Empire with spare capacity to do something about it would not have let Teutoburg be the last word in the conquest of Germania, it is very unlike their previous behaviour when losing battles.

Especially in the east, the Persians were the Romans only peer enemy and a lot of resources were spent on securing the eastern frontier.

[jimmy olsen]

That's fair Maladict. I can't believe I forgot about Mesopotamia.

However, the reason they couldn't hold on to the places you mentioned was logistical. Too far from Rome. Too far from the sea.

With a canal Yemen is only 2/3 the distance of Hadrian's Wall. And it and the Kingdom of Auxum are right on the coast.

[jimmy olsen]

Yes, and the over-stretch was already visible under Augustus. A Roman Empire with spare capacity to do something about it would not have let Teutoburg be the last word in the conquest of Germania, it is very unlike their previous behaviour when losing battles.

Germania was a worthless forest at the time. If it was worth it they would have tried harder. They still managed to send punitive expeditions deep into Germania for centuries after the battle of Teutonburg Wald

[Threviel]

Then why did they try to conquer it at all? The Romans tried, were defeated and withdrew due to lack of resources. The Emperor said to be crying over three lost legions which implies that it was a great drain of imperial resources.

And then after that build a canal through desert with tens of thousands of labourers? The Romans were far cleverer than that, had they tried we would probably be talking about the crisis of the first century.

And if they had deemed it possible to do with just the two legions stationed in Egypt they would probably have done it, they were no fools and would have seen the benefit. But the Romans, with all the information they had that we do not, deemed it not beneficial enough.

[Maladict]

Yes, and the over-stretch was already visible under Augustus. A Roman Empire with spare capacity to do something about it would not have let Teutoburg be the last word in the conquest of Germania, it is very unlike their previous behaviour when losing battles.

It wasn't the last word though. The Romans kept campaigning and conquering territory throughout the first century.
But I agree overstretch, and pressures elsewhere, meant they probably could never have held Germania.

[Threviel]

Yeah, I know, the Romans slapped the barbarians around for a few more centuries. But it was the last word in any serious attempt to conquer Germania.

It was more an example of imperial overstretch. They couldn't hold Germania due to lack of resources in the quiet safe part of the empire against enemies they routinely slaughtered. There's no way they could build a Suez canal and conquer Ethiopia and Arabia whilst their only serious peer enemy was just around the corner without exasperating that overstretch.

[Maladict]

Yeah, I know, the Romans slapped the barbarians around for a few more centuries. But it was the last word in any serious attempt to conquer Germania.

The occupation of the Agri Decumates was a pretty significant extension of territory, even if it wasn't a wholesale attempt to reconquer all Germania.

[The Larch]

An enormous sum, but considering the likely need for heavy security as well as many trained cameleers perhaps not that surprising.  Still as big as that cost was, it was just 9 percent of the total value of the cargo.  So the overall economic impact of a canal, while not insignificant, doesn't seem to be worthwhile enough to justify the project.

The bigger picture is that even though the luxury trade was valuable in cash terms, the heart of the Roman economy was the grain and olive oil trades and the heart of the fiscal system was the land tax. From a security perspective, the grain trade was obviously a much higher priority than spices and incense.

While I do think that the canal would have significant economic benefits, I'm not arguing that any Emperor would build the canal with that in mind.

An Emperor would build it so that they could more easily support attempts to conquer the wealthy city states of the Red Sea, the Kingdom of Saba (Yemen) and the Kingdom of Auxum (Ethiopia).

Which would not only add gold mines, frankincense and myrrh to the Empire, but would also clear out the pirates that infest the Sea. That, as much as a canal that was accessible year round, would encourage trade.

What need was there for Rome to conquer all those places? They already traded extensively with them to acquire those luxury goods and had a significant naval presence in the Red Sea without a canal. That's videogame thinking.

[jimmy olsen]

What need did Rome to conquer anything outside of the Italian peninsula?

Land, glory and wealth. Same reason they conquered everywhere else.

Augustus did try to conquer Yemen.

[The Larch]

What need did Rome to conquer anything outside of the Italian peninsula?

Land, glory and wealth. Same reason they conquered everywhere else.

Augustus did try to conquer Yemen.

And they had other targets that were much more feasible, Augustus himself, besides acquiring and consolidating Egypt (no small task after centuries of Ptolomeian mismanagement), expanded the Empire in the Balkans, Central Europe and Anatolia. Calling the expedition to Yemen a conquest campaign is overplaying it. Its main objective was making the Sabaeans tributaries to Rome, and upon its failure they quickly forgot about it. Augustus was already weary of overextending Rome's frontiers, so imagining wild conquest campaigns in Africa and Arabia is a pointless fantasy.

[mongers]

Any particular reason why this canal should have been 30-90 metres wide?

Were they thinking of tacking the ships up and down it?

Or perhaps avoiding any chance of that not uncommon 21st mishap in the current Suez canal?

[Josquius]

What need did Rome to conquer anything outside of the Italian peninsula?

Land, glory and wealth. Same reason they conquered everywhere else.

Augustus did try to conquer Yemen.

It was mostly about security no?
Rome invaded gaul because the Gauls kept invading Italy. Britain because they were helping the Gauls. Same too many places.

[The Larch]

What need did Rome to conquer anything outside of the Italian peninsula?

Land, glory and wealth. Same reason they conquered everywhere else.

Augustus did try to conquer Yemen.

It was mostly about security no?
Rome invaded gaul because the Gauls kept invading Italy. Britain because they were helping the Gauls. Same too many places.

Caesar claimed Britannic support for Gauls for his campaign there, but it's unclear if this was real of Caesar covering his ass post-facto. Afterwards, when it was conquered, it was initially a net loss for Rome, as the trade with Britannia earned them more money than what they initially received as taxes from the conquered province.

[The Larch]

Rather interesting to check around about what source material exists concerning the Roman trade with India and Arabia. The Roman Empire was obviously quite big and had an extensive bureaucracy for an ancient polity and the trade was quite significant.  Yet there are basically just 3 original sources for the scope of the Eastern trade that the literature seems to cite over and over:
(1) a passage in Pliny's Natural History that indicates Rome generated 100 million sesterces of revenue annually - a sizable amount but a lot less than the 1 billion claimed with McLoughlin.
(2) a reference in Strabo to 120 Roman ships sailing the trade route annually.
(3) a second century papyrus found in south-western India documenting a trade finance transaction for a shipment of Indian goods to Rome - the "Vienna Papyrus"

The literature  I saw focused a lot on the Vienna papyrus.  It documents the shipment in considerable detail and values the shipment at 7 million sesterces.  Multiply that by Strabo's 120 ships and you get 840 million - not that far from McLoughlin''s 1 billion.  Of course there are lot of questionable assumptions there.

Focusing on the specific question of a canal though - the shipment documented in the papyrus was landed at a Red Sea port and carried by camel to Coptos - a city on the bank of the Nile. So the trade benefit of the canal would be eliminating to camel trans-shipment to Coptos. 

The papyrus indicates the cost of the trip to Coptos was 20 talents, or about 640,000 seterces.  An enormous sum, but considering the likely need for heavy security as well as many trained cameleers perhaps not that surprising.  Still as big as that cost was, it was just 9 percent of the total value of the cargo.  So the overall economic impact of a canal, while not insignificant, doesn't seem to be worthwhile enough to justify the project.

The bigger picture is that even though the luxury trade was valuable in cash terms, the heart of the Roman economy was the grain and olive oil trades and the heart of the fiscal system was the land tax. From a security perspective, the grain trade was obviously a much higher priority than spices and incense.

Most of the places I checked use as its largest reference a 1st century AD document, the "Peryplus of the Erythreaean Sea", that names trade routes from Egypt's ports in the Red Sea down to the Horn of Africa and beyond (the southernmost port named is in modern Tanzania), the Arabian coast and further into modern Pakistan and India. It has a pretty extensive wiki article, in case anyone is interested: https://en.wikipedia.org/wiki/Periplus_of_the_Erythraean_Sea

[jimmy olsen]

Any particular reason why this canal should have been 30-90 metres wide?

Were they thinking of tacking the ships up and down it?

Or perhaps avoiding any chance of that not uncommon 21st mishap in the current Suez canal?

That's what the article postulates. It does seem overly wide and deep and if it could have been done significantly smaller, it would obviously make it more doable as less work would have to be done.

The Erie canal for example was originally only cut 40 feet (12 m) wide and 4 feet (1.2 m) deep., for example.

And even if you wanted two trireme's to be able to travel past each other in different directions, rather than use barges, it doesn't seem like it would have to be anywhere near as big. Where Roman ships that much bigger than Athenian ones?

https://en.wikipedia.org/wiki/Trireme#Dimensions

Excavations of the ship sheds (neōsoikoi, νεώσοικοι) at the harbour of Zea in Piraeus, which was the main war harbour of ancient Athens, were first carried out by Dragatsis and Wilhelm Dörpfeld in the 1880s.[24] These have provided us with a general outline of the Athenian trireme. The sheds were ca. 40 m long and just 6 m wide. These dimensions are corroborated by the evidence of Vitruvius, whereby the individual space allotted to each rower was 2 cubits.[25] With the Doric cubit of 0.49 m, this results in an overall ship length of just under 37 m.[26] The height of the sheds' interior was established as 4.026 metres[citation needed], leading to estimates that the height of the hull above the water surface was ca. 2.15 metres. Its draught was relatively shallow, about 1 metre, which, in addition to the relatively flat keel and low weight, allowed it to be beached easily.[citation needed]

EDIT: It just occurred to me that the ships plying the route from India to Africa might indeed be significantly larger, but even so, one would think 30 meters would be a maximum width needed, not a minimum.