I think technological advantage—specifically sailing technology—probably played a much larger role in Afonso’s takeover than it would seem from a quick read. Key pieces:
Monsoons
Lateen sail
Monsoons: wind around India blows consistently Southwest for half the year, and Northeast for the other half. IIRC from Braudel, this made trade in the Indian ocean highly predictable: everyone sailed with the wind at their back and ran consistent one-year circuits. As you mention:
The Indian Ocean contained most of the world’s trade at the time, since it linked up the world’s biggest and wealthiest regions.
I’d guess that the monsoons were probably a bigger factor here than vicinity to wealthy regions. In particular:
Europe is just coming out of the Middle Ages and does not have an obvious technological advantage over India or China or the Middle East, and has an obvious economic disadvantage.
Europe had less total wealth (because it had a smaller population) and was behind technologically in some ways (e.g. metallurgy), but even in the 15th-16th century Europe was considered “wealthy” on a per-capita basis. In particular, Europe had much more per-capita capital goods, even before the industrial revolution—especially mills and machinery. Braudel covers a lot of this.
Anyway, monsoons. Consistent wind direction, with an annual cycle. That makes the lateen sail a major strategic advantage: Portugese ships would have been able to tack upwind, a technique which was basically unheard of in the Indian ocean at the time. (On top of that, the Portugese were happy to sail in open ocean at that time and were accustomed to navigating away from land—unlike the Indian ocean locals. Again, Braudel talks about this a fair bit.) So the local navies were presumably stuck at one end of the ocean for six months, while the Portugese had free reign to sail around wherever they wanted. And to top it all off, even if the local navies did manage to catch them, the Portugese could just sail out to open ocean, and the locals wouldn’t want to follow.
Now combine that with supply: throughout most of history, a single ship could carry as much supplies as about 4000 horses (source: Logistics of the Macedonian Army). For any island garrisons, or for garrisons surrounded by desert, horses wouldn’t even be an option. Thus the importance of naval dominance even for land wars in premodern times: an overland supply train was extremely expensive at best, and often entirely infeasible. Control the water, and the enemy starved.
Put all that together, and Afonso’s plan looks less ridiculously ambitious. They had a technological advantage which was perfectly suited to the problem.
Update: According to the wiki article on lateen sails, they existed for several hundred years in the Mediterranean before spreading to the Atlantic, and the Nile, and then finally they arrived in the Indian ocean with the Portuguese, at which point the locals quickly adopted it on their vessels also. (Within 20 years!)
What the hell? Why did it take so long? If it was so good that it gave a huge advantage, such that everyone copied the design within two decades of the Portuguese arrival… why did no one notice this for almost a thousand years? Surely there were travelers who sailed on both the Med. and Red seas, for example. Surely the Ottomans and Mamelukes, who maintained fleets in both the Med. and the Indian Ocean, should have been able to realize that the lateen sail was a thing and would be useful? (Especially since being able to sail against the wind seems super useful precisely when the wind doesn’t change direction very much, e.g. in monsoon-regions like the Indian Ocean) Also apparently the pacific islanders independently invented the lateen sail, yet it didn’t spread from there to the Indian Ocean either. I am very confused.
Thanks for this, I didn’t know about that stuff. Perhaps I should read Braudel. This makes me more confident that technology was a necessary factor. If I were motivated to do so, I’d read through the stories of Afonso’s success in more detail and try to see whether open-sea sailing and/or sailing against the wind played a factor.
Braudel is both long and dense, and I wouldn’t recommend the second two volumes at all, but the first volume is probably the single best history book I’ve read. Beware that his understanding of economics is pretty poor—trust his facts, but be wary of his interpretations.
I think technological advantage—specifically sailing technology—probably played a much larger role in Afonso’s takeover than it would seem from a quick read. Key pieces:
Monsoons
Lateen sail
Monsoons: wind around India blows consistently Southwest for half the year, and Northeast for the other half. IIRC from Braudel, this made trade in the Indian ocean highly predictable: everyone sailed with the wind at their back and ran consistent one-year circuits. As you mention:
I’d guess that the monsoons were probably a bigger factor here than vicinity to wealthy regions. In particular:
Europe had less total wealth (because it had a smaller population) and was behind technologically in some ways (e.g. metallurgy), but even in the 15th-16th century Europe was considered “wealthy” on a per-capita basis. In particular, Europe had much more per-capita capital goods, even before the industrial revolution—especially mills and machinery. Braudel covers a lot of this.
Anyway, monsoons. Consistent wind direction, with an annual cycle. That makes the lateen sail a major strategic advantage: Portugese ships would have been able to tack upwind, a technique which was basically unheard of in the Indian ocean at the time. (On top of that, the Portugese were happy to sail in open ocean at that time and were accustomed to navigating away from land—unlike the Indian ocean locals. Again, Braudel talks about this a fair bit.) So the local navies were presumably stuck at one end of the ocean for six months, while the Portugese had free reign to sail around wherever they wanted. And to top it all off, even if the local navies did manage to catch them, the Portugese could just sail out to open ocean, and the locals wouldn’t want to follow.
Now combine that with supply: throughout most of history, a single ship could carry as much supplies as about 4000 horses (source: Logistics of the Macedonian Army). For any island garrisons, or for garrisons surrounded by desert, horses wouldn’t even be an option. Thus the importance of naval dominance even for land wars in premodern times: an overland supply train was extremely expensive at best, and often entirely infeasible. Control the water, and the enemy starved.
Put all that together, and Afonso’s plan looks less ridiculously ambitious. They had a technological advantage which was perfectly suited to the problem.
Update: According to the wiki article on lateen sails, they existed for several hundred years in the Mediterranean before spreading to the Atlantic, and the Nile, and then finally they arrived in the Indian ocean with the Portuguese, at which point the locals quickly adopted it on their vessels also. (Within 20 years!)
What the hell? Why did it take so long? If it was so good that it gave a huge advantage, such that everyone copied the design within two decades of the Portuguese arrival… why did no one notice this for almost a thousand years? Surely there were travelers who sailed on both the Med. and Red seas, for example. Surely the Ottomans and Mamelukes, who maintained fleets in both the Med. and the Indian Ocean, should have been able to realize that the lateen sail was a thing and would be useful? (Especially since being able to sail against the wind seems super useful precisely when the wind doesn’t change direction very much, e.g. in monsoon-regions like the Indian Ocean) Also apparently the pacific islanders independently invented the lateen sail, yet it didn’t spread from there to the Indian Ocean either. I am very confused.
Thanks for this, I didn’t know about that stuff. Perhaps I should read Braudel. This makes me more confident that technology was a necessary factor. If I were motivated to do so, I’d read through the stories of Afonso’s success in more detail and try to see whether open-sea sailing and/or sailing against the wind played a factor.
Braudel is both long and dense, and I wouldn’t recommend the second two volumes at all, but the first volume is probably the single best history book I’ve read. Beware that his understanding of economics is pretty poor—trust his facts, but be wary of his interpretations.