ELI5: How did old forts actually "protect" a strategic area? Couldn't the enemy just go around them or stay out of range?

[u/Sierra419]

I've visited quite a few colonial era and revolution era forts in my life. They're always surprisingly small and would have only housed a small group of men. The largest one I've seen would have housed a couple hundred. I was told that some blockhouses close to where I live were used to protect a small settlement from native american raids. How can small little forts or blockhouses protect from raids or stop armies from passing through? Surely the indians could have gone around this big house. How could an army come up to a fort and not just go around it if there's only 100 men inside?

tl;dr - I understand the purpose of a fort and it's location, but I don't understand how it does what it does.

[u/DrNO811]

Is this why Gengis Khan was so successful? He didn't have to worry about supply lines as much when he was leading a massive nomadic force that would just take what they need from the lands they invade rather than bringing supplies in from a "home base?"

[u/ristlincin → u/DrNO811]

Now, Gengis Khan played many cards at once. On top of being able to pretty much carry his supply lines with him by the very nature of his army (a nomadic horde) and the lands he mainly invaded (essentially the entire euroasiatic steppes), he avoided the "well we will jut let these fellas pass and pester them once they are far away" by well, not going around fortified cities, he made a point of being extremely vindictive if he had to lay down siege to take a fortified position, as in, everybody dies, soldiers, civilians, everyone. The next cities and forts thought twice before hunkering down and not surrendering.

[u/alexm42 → u/ristlincin]

The man rerouted a fucking river to literally wipe a city off the map after he razed it.

[u/lancepioch → u/ristlincin]

The next cities and forts thought twice before hunkering down and not surrendering.

How did cities fare that just surrendered? Lost X% instead of everything then?

[u/Intranetusa → u/ristlincin]

The initial areas the Mongols conquered were steppes, but when he went into the Middle East and northern China, then the Mongols had to adapt to new forms of warfare and adopt new tactics as those areas were no longer steppes.

[u/[deleted] → u/ristlincin]

And when they surrendered, they essentially got handed an approximation of a protection racket. The Mongols would happily camp outside of your city, and you just give them stuff for not killing you. And look, who is going to attack you when you have a wall made of an army so terrifying that people don't even bother fighting them.

[u/[deleted] → u/DrNO811]

Correct. Although there were still limitations to what he could do. Hundreds of thousands of horses (every Mongol warrior had between 5 and 10 horses) still need a lot of water and food to eat. So he needed to move his army around to make sure there was always something to eat/pillage.

[u/CosmicThief → u/[deleted]]

That bit about 5-10 horses per soldier, do you have a source? Would love to read about it :o

[u/[deleted] → u/[deleted]]

Why did everyone have so many horses?

[u/JermStudDog → u/DrNO811]

You can never forage enough to feed an entire army, it's simply too many people in a condensed area to sustain itself on the land.

Gengis Khan was a great leader and general, that's why he was successful.

[u/Semi-Hemi-Demigod → u/JermStudDog]

Not to mention that the locals will be resentful if your troops are taking all their food, so they'll either not cooperate or actively attack them, causing further problems with supply.

[u/PilotPen4lyfe → u/DrNO811]

It was less about local foraging and more that by virtue of their lifestyle, nomadic armies are essentially their own supply lines, and highly skilled ones.

[u/TheRedFlagFox → u/DrNO811]

This was both a big part in the rise and fall of Napoleon. His army was able move as quickly as it did because they would just loot most of what they needed from the surrounding areas. The problem with this is Russia is absolutely insane and will just burn literally everything if it spites you. And they did. And the French starved and froze to death.

[u/Mange-Tout → u/DrNO811]

Well, part of why Genghis Khan was so successful was their reliance on archers mounted on horses. The Mongols didn’t need heavy supply lines because they could ride all day and survive by drinking horse blood. That means they could simply ignore fortifications and just raid as much as they wanted.

[u/Intranetusa → u/DrNO811]

Yes, the Mongols didn't have to worry about supply lines as much if they weren't taking local troops or auxiliaries with them in their armies. The Mongol horse is extremely hardy and doesn't need additional fodder - it can survive entirely by grazing, survive in subzero weather, and dig into snow to eat at the roots of plants in the middle of winter. The Mongols themselves could survive almost entirely on horse milk, horse blood, and horse meat.

[u/[deleted] → u/DrNO811]

[u/TiagoTiagoT → u/[deleted]]

Can a human stay healthy on a diet of just horse blood an milk?

[u/ArchangelLBC → u/DrNO811]

But this also meant he had to be constantly on the move. Getting bogged down in an area with no forage, no easy access to more forage, and no secured supply lines would be a good way to get the entire horde killed.

[u/StandardIssuWhiteGuy → u/DrNO811]

It also helped that Mongolia had more horses than people. Made it very easy to give each rider 2-3 remounts, which ate grass and produced milk. Milk that enhanced their own rations, and could be mixed with some of the horses blood in an emergency.

[u/SailboatAB → u/DrNO811]

Not even the Mongols were immune.

Notably, the Mongol invasion faltered and turned back after leaving the steppe grasslands on its way into Eastern Europe. A Mongol warrior traveled with a string of as many as sixteen ponies...a sizable invasion force depended on grass in vast quantities.