An Ocean With a Timetable

The Indian Ocean is the only ocean in the world whose winds reverse on a schedule.

From roughly April to September the southwest monsoon blows from Africa and Arabia toward India and Southeast Asia. From October to March the northeast monsoon blows back. A merchant setting out from Aden knows, before the anchor comes up, in which month the return voyage becomes possible.

That single fact organises everything. Long-distance sailing elsewhere in the pre-modern world was a gamble against wind and current; here it was a timetable. And because the return could not happen until the wind turned, merchants spent months in foreign ports, which is how you get permanent communities of Gujarati traders in Malacca, Arabs in Canton, Chinese in Java, Armenians everywhere, living under their own headmen and their own law, marrying locally, and staying.

The Indian Ocean before 1500 was, by a considerable margin, the most commercially sophisticated system in the world, and its most striking feature is what it lacked: nobody was trying to control it.

There was no dominant navy. No state claimed the sea. No power attempted to make the trade a monopoly. Instead, port cities from Kilwa and Malindi down the African coast to Hormuz, Calicut, Melaka and Canton competed to attract merchants: by offering secure warehousing, honest weights, available credit, translators, and courts that would enforce a contract against a local as readily as against a foreigner.

This is worth dwelling on, because it inverts the usual assumption that trade requires a hegemon to police it. The Indian Ocean ran for centuries on competitive port governance and merchant self-regulation. A ruler who squeezed too hard found the ships calling somewhere else the following season, which is a discipline no treaty imposes as reliably.

We know what the merchants themselves were doing because of an accident of religious practice. A storeroom in a Cairo synagogue preserved several hundred thousand documents over nearly a thousand years (the Cairo Geniza) because texts containing the name of God could not be destroyed and were stored instead. What accumulated was not scripture but the working paper of ordinary life: letters, accounts, contracts, complaints.

The India traders in that archive ran partnerships spanning thousands of miles, extended credit without collateral to people they had never met, sent agents with discretionary authority, insured cargoes informally by splitting them across ships, and settled disputes through community pressure rather than courts. These are sophisticated commercial institutions, in the eleventh century, invisible in any official record.

Then there is the strangest episode in the ocean's history, which is about a capability abandoned.

Between 1405 and 1433 the Ming admiral Zheng He led seven expeditions across the Indian Ocean, reaching Arabia and East Africa. The fleets were enormous by any contemporary standard: hundreds of vessels, tens of thousands of men, ships far larger than anything Europe would build for a century. Their purpose was not commerce and not conquest but diplomacy: collecting tribute, installing friendly rulers, and enrolling the ocean's states in a Chinese order.

And then the court stopped them, restricted shipbuilding and let much of the record be destroyed. The reasons were internal. The cost was enormous, a hostile faction held that the money belonged on the northern frontier and the Grand Canal, and the voyages returned prestige rather than revenue. Whatever one thinks of the decision, it is the clearest case in history of a state deliberately giving up a capability it possessed and nobody else had.

Sixty-five years later Vasco da Gama arrived with four ships.

What the Portuguese brought was not better goods (they had almost nothing Asia wanted) and not better ships for the trade. It was cannon, and a new idea about what to do with them: tax the sea itself. The cartaz system required Asian vessels to purchase a Portuguese pass and call at Portuguese ports, on pain of seizure. It is protection selling, run as a state enterprise.

It did not sweep Asian merchants away. They continued to carry the overwhelming majority of the ocean's trade for centuries, often by rerouting around Portuguese control, and the Portuguese network was always thin, undermanned and dependent on local alliances. The transition to genuine European commercial dominance comes much later and by different means.

But the principle arrived in 1498, and it was new to that ocean: that a state might treat the sea as something to be owned.