Horses were domesticated for riding at least 6 000 BC . They were extensively used in warfare . Stirrups first show up in the archeological record about 400 AD .
The Question !
Why did it take so long ?
The standard answer is human stupidity .
But even I find it hard to swallow that expert leather workers in warrior societies as diverse as the Assyrian , Persian , Greek ,Roman , Scythian and Chinese empires took a whole 5 000 years to think of stirrups . Remember that the weapon-systems over this period were essentially unchanged : sword , spear , shield , archery , slingers .
There are two exceptions , and it involves the horse . The chariot is a minor one . The size of the horse is the main difference.
Chariots developed as a battle platform precisely because horses were not large enough to carry their own armour as well as a armoured soldier . But two or four lightly armoured horses could pull a chariot with two armoured soldiers.
Imagine two mirror armies , A and B . A had chariots , but B does not .
They squared up in a set-piece battle .
The chariots of A were used mainly as a platform for distance weapons . Drivers drove past the enemy front . The weaponeers threw spears , shot arrows and used sling-shots . When out of ammunition , they retired to reload . This could be kept up indefinitely , since they could retire faster than their enemy could pursue .
Army B has the choice of being nibbled to death or attacking .
If the enemy B attacks on a wholescale basis , they are at a big disadvantage , since they were attacking a fixed position . The usual odds are 3 to 1 .
Thus , A can always win by forcing a battle of strategic offensive , tactical defensive .
Any mistakes by army B (like a gap opening) , was exploited by using the chariots as a shock strike weapon .
So the first users of chariots had a big advantage . What was the defense?
1. Attack the weak point : the horses .
The key was in the small size of the horses . They were too small to carry effective armour against close-up cavalry or chariot attack . Cavalry attacks against chariot horses degraded chariots to an expensive luxury . Chariots were more expensive to maintain , so chariots were eventually phased out in favour of cavalry . Cavalry remained essentially an anti-cavalry force until larger horses were bred .
2. Disciplined infantry capable of shielding against projectile weapons , but also maintaining a spear-wall against horse chariot or cavalry shock-attack . Note that this is the definition of the Greek phalanx . Unarmoured horses will refuse a wall of spearpoints .
3. Breed large numbers of horses big enough to carry their own armour , as well as a armoured rider . This could only happen in organizations with large resources : Empires like the Roman or Chinese .
I would imagine that breeding large war-horses was a late Roman-Empire effort . Only they had the resources purely military program of this magnitude . ( Something like DARPA or NASA ). The genes filtered through to the civilian population , enabling economical heavy ploughs and the heavy-duty horse-collar that revolutionized western agriculture .
Something similar probably happened in the Middle-East : the Arabian horse . This smacks of a massive Roman breeding program to produce a horse big and tough enough for local conditions . A sine-qua-non for the Arab expansion .
The same genes would have found their way to areas like Mongolia . Compare Przewalski’s horse against a mongol horse . The Mongol horse is not much bigger , but it is much stouter in all ways . Over- powered for a horse evolved on the steppes for purely civilian and local tribal-warfare purposes .
Everybody knew about stirrups .
Stirrups were only used when there were horses large enough for the complete weapon –system : the armoured knight .
It worked .
Ask Attila at Chalons . The battle was a tactical draw , but a strategic defeat . What is important is that this was the deliberate design in which the large horses were a mere component .
Even if Aetius had lost at Chalons , the Huns still would not have won .
The design was strategic defensive , tactical offensive .
Strategically fortresses ( a Roman speciality ) , with nearly invulnerable armoured strike-forces can hold against any attack as long as the armoured forces remain intact
At that time , it seemed as if limitless numbers of barbarians from the steppes could hurl themselves at the ramparts of civilization and beat them down by sheer numbers . But the numbers were not limitless . They were co-ordinated into schwerpunkts , with nothing behind them . The steppes could not possibly have as many people as the civilized , agricultural areas . They could only win by defeating the civilized areas in detail . But fortified points and armoured knights could prevent defeat , but not ensure victory . A standoff ensued . No empire , but lots of baronies . Some argue that this is a more natural state for humans . This held until effective use of gunpowder.
The extreme ratio favouring defenders in a properly constructed defensive fortress can be seen in examples: the siege of Malta (circa1564) : about 70 000 Ottoman troops , including 10 000 Janisseries , could not break defenses manned by about 9 000 knights . Constantinople ( 120 000 vs 3 000 ) . Etc,etc,
I wonder if the Roman who instituted the breeding program of the horses knew that it meant the end of classical Empires . I think he did , but the consequences of doing nothing was worse than having little pocket-empires (note : not city-states : no single fortress could survive on its own :the attacker had to be whipsawed between different fortresses .)
This Roman must have lived just before the split of the Roman empire . He must have been of high rank .He did not brag about it . Therefore not an emperor . He would have been perceived as a traitor . Since he was so effective that he sculpted the next 800 years , if he wanted to retire into anonymity , let him .
Could the Mongols have won in Western Europe?
The Mongols won initially against lightly fortified towns like Kiev . Even then ,they paid a heavy price . They only had about 300 000 mongol troops , plus an unknown and totally unreliable number of slaves .
Mongols won by getting inside the enemy’s control loop .
The way to beat the Mongols (and how the Chinese could have beaten them ) is by killing their horses . Horse diseases spring to mind .