The Silk Road

The term was invented in 1877 for routes that were never a road, and deciding what it can honestly refer to is the first piece of work the subject asks for.

Almost everything the subject knows comes from three or four accidents of preservation in dry sand, and reading any claim about the routes means asking first which accident it rests on.

A loaded camel has a payload, an appetite and a range, and those three numbers fix the shape of the route and decide which goods could cross at all.

Since no caravan could carry its own food, the towns that sold fodder and water were not stops on the route but the route itself, and their water is the reason they existed.

The freight model predicts a cargo of dense luxuries, the excavated goods confirm it, and the excavated documents then show that the traffic was far smaller than anyone had assumed.

A standard bolt of silk was a unit of currency as well as a fabric, and the largest mover of it into Central Asia was the Chinese state paying soldiers and buying horses.

An Iranian-speaking people from the valleys around Samarkand ran the relay for six centuries, and their own abandoned mail shows how a trading diaspora solves trust, credit and language.

Religions do not automatically move with trade, and the reasons Buddhism did are institutional: monasteries were infrastructure merchants needed, and donation was a doctrine merchants could use.

Zoroastrianism, Manichaeism, the Church of the East and Islam all used the same roads, and comparing what happened to each says what actually makes a religion portable.

An object crosses Asia in a season and a skill takes centuries, and paper, silk and sugar show why the difference is a thousandfold.

For roughly a hundred years the whole route lay under one authority, which is the closest thing the subject has to an experiment: hold the geography fixed, remove the borders, and see what changes.

The plague is now the best evidenced cargo in the whole subject, because a cemetery in Kyrgyzstan and a genome published in 2022 dated its departure to within a year.

A single wreck of the 820s held sixty thousand pieces of pottery, which is more cheap ceramics than the overland route could have carried in its whole history, and freight arithmetic says why.

The Ottomans did not close the road in 1453, and the caravans were still crossing Asia in the 1850s, so the ending has to be rebuilt from relative costs rather than from a conquest.

A term coined in 1877 for routes that had faded is now the branding of the largest infrastructure programme on earth, and tracing its uses is the last piece of work the subject asks for.