Thread by @byzantinemporia

Ridiculous hypothesis that might be true:

For thousands of years, the migrations of people across the Great Eurasian Steppe almost always went from west to east.

What if this was driven by the wind and the sun?

Nomadic migrations were the engine of history. Massive tribal confederations would come thundering off the steppe every so often, disrupting the repose of the civilized world from Europe to China.

A pattern seen from Antiquity through the Middle Ages.

byzantinemporia.com/great-eurasian…

These confederations coalesced amidst the endemic warfare of the steppes, when tribal leaders attracted large followings.

But it was pretty difficult for large confederations to form, all things considered.

First, a tribe had to grow through natural increase or gain followers by winning local prestige. This meant either successfully defending itself or successfully attacking others.

Either way, it meant victory in war.

The larger a tribal confederation got, the more success it had; the more success, the easier time it had attracting followers.

Eventually it might gain “critical mass”, when it could make truly massive conquests.

This is what happened with some of the more famous confederations in history, like the Scythians, Avars, Khazars, or Pechenegs. Never mind the truly world-transforming ones, like the Huns, Turks, or Mongols.

But this could only happen after a long string of nearly uninterrupted victories.

The death of a charismatic leader, a betrayal by a tributary, or even a single defeat in battle could shatter a nascent confederation.

So what did the wind and sun have to do with it?

The wind blows in many direct on the steppe, but some of the fiercest blow out of Siberia six months of the year (the Siberian High). This could have a tangible effect on battles.

The tribes to the east would have the wind at their backs, meaning their arrows flew farther and their horses charged faster.

Meanwhile their enemies suffered the opposite effects, and their eyes were stung by the bitter wind.

Battles usually started in the morning. This meant that tribes to the west would have the rising sun in their eyes—it was a common tactic for armies to try to fight with their back to the sun.

This wouldn’t be a decisive advantage, obviously. It would only give the eastern tribes a leg up, and only when they held the eastern side of the battlefield, which wouldn’t always be the case.

But if a leader has to win an uninterrupted string of victories, even a small advantage in single battles translates to a substantial advantage in war, snowballing into a huge advantage over time.

A slightly higher probability of success compounds over time like interest.

In other words, the important differences are on the margins.

In genetics, it only takes a slight fitness advantage for a gene to sweep through a population; likewise, nomadic tribes with a slight fitness advantage could sweep across the steppe.

There is of course another factor at work.

Most histories describe tribes being pushed west by neighbors to the east. But tribes were also attracted by the promises of rich civilizations such as Persia and Rome.

This had a bad effect on the tribes themselves, though. The easier the plunder, the softer they became. The Romans even encouraged trading luxury items with the barbarians in order to curb their warlike tendencies.

This only made them vulnerable to hungrier tribes to the east, who heard tales of their neighbors’ wealth. Tribes kept getting pushed west because they became richer and weaker.

In the Far East, on the other hand, the steppe ran all the way to the Pacific.

Although China had a similar corrupting influence on steppe peoples, it lay far to the south, not along the axis of east-west migrations, as Europe and Persia roughly do.

China country was also protected by the Gobi Desert and had a very high population density, which made it hard for nomadic raiders to make large, permanent conquests.

They still tried and occasionally succeeded, but it was far easier to expand westward.

This is the more obvious and believable explanation. But human affairs are complex, and it is impossible to dismiss the rising sun and prevailing winds.

But complexity brings mystery, and we can never truly know.