But the monsoons were not the only consideration in determining the optimal routes and their termini. Geography also mattered. As Indian Ocean historian R.N. Chaudhuri paraphrases the son of Portuguese conqueror Afonso de Albuquerque: ‘There are three places in India … which serve as markets for all the trade in merchandise in that part of the world and are the principal keys of it. The first is Malacca, the second Aden, and the third Hormuz. All three command the entrance and the exit in narrow sea passages.’5 Beyond their mastery of monsoons and straits, ports in the age of sail could flourish because they provided safe – or ‘noble’ – havens. Aden had a naturally deep harbour that sheltered from the winds and a hard enough sea-floor complementing its depth to host oceangoing ships. The wondrous account of Sulayman, the ninth-century itinerant merchant, similarly indicates the reasons Siraf, on the Persian shores of the Gulf, became the early medieval entrepôt for the western Indian Ocean:
Most of the Chinese boats are loaded at Siraf and the goods are carried to Siraf from al-Basra, Uman and other [ports], and then they are loaded on the Chinese boats at Siraf. This is because the waves are abundant in this sea and the water is at a low [level] in some places … So when the goods are loaded at Siraf, they store sweet water from there and set sail.6
Aden and Siraf, however, languished from the sixteenth to nineteenth centuries, and while Aden became a major port after being colonised, Siraf never regained its early prominence. Politics and social relations were often more important than geographic felicity. So many of the ports of the Red Sea and the coasts of the Persian Gulf were placed there despite their location. Mudflats, treacherous coral reefs, and access only to brackish water supplies and meagre ships’ stores did not prevent the emergence of ports in inhospitable locales. Access to hinterlands, credit, networks of trade, and seafaring skills all played a role.
Long before Europeans found the maritime route to the Indian Ocean, Arabs and the archipelago peoples of the eastern Indian Ocean before them had already developed sophisticated navigational methods for travel across the unruly waters. In his beautiful manual of navigation, the fifteenth-century Arab seafarer Ahmad ibn Majid al-Najdi writes about the knowledge required to traverse the perilous deeps that lay between the Arabian Peninsula and the far shores of Asia and Africa:
Know oh reader, that sailing the sea has many principles. Understand them: the first is the knowledge of lunar mansions and rhumbs and routes, distances, latitude measuring, signs (of land), the courses of the sun and moon, the winds and their reasons, and the seasons of the sea, the instruments of the ship … It is desirable that you should know about risings and ‘southings’ and the methods of taking latitude measurements and their variations and graduations, the risings and settings of the stars, their latitudes, longitudes and distances and their passing the meridian … It is also desirable that you should know all the coasts and their landfalls and their various guides such as mud, or grass, animals or fish, sea-snakes and winds. You should consider the tides, and the sea currents and the islands on every route.7
The accumulated corpus of navigation knowledge came not only from a panoply of navigation manuals written by seasoned seafarers over the course of centuries, but also from the quotidian experience of nakhodas (captains) aboard both oceangoing and coastal ships. This vast archive of experience and memory also served to make ephemeral sea routes more concrete.
But, beyond geophysical accident and the congealed skills of seafarers in great ports, what mattered greatly to the making of routes in the Indian Ocean was relations of trade and pilgrimage that made sea routes so much more than imagined lines on maps. If port cities were designated neutral or free ports, they attracted these transoceanic networks of trade more readily. As trade relations flourished, so did credit, exchange, and trade. Merchants and other traders could borrow money in one port for the purchase of goods and repay in another port. When ports flourished, taxes and fees for the rulers followed.
We know a great deal about transoceanic networks of merchants throughout the Indian Ocean’s history, where ties of kinship and community lubricated the machinery of exchange. But kinship and trust alone did not suffice; trade networks also depended on legal frameworks and mechanisms for enforcement of contracts.8 The routes of exchange were many-cornered9 and goods and people – merchants, slaves, soldiers, adventurers, imperial officers, seafarers, immigrants and pilgrims – were transported between the coasts of East Africa, Arabia, India and the Southeast Asian archipelagos. Long before the Portuguese, Dutch, French, and British East India Companies forcefully inserted themselves into these pre-existing trade networks,10 precious metals, spices, timber, aromatics, and other goods travelled aboard cargo ships across the waters and along the coasts. Many of these routes and ports of trade became objects of European conquest precisely because of their abundance, the sophistication of their mechanisms of exchange, the depth of their infrastructures of trade, and their extensive and longstanding connections to their hinterlands, to their coastal neighbours, and across the seas.
The Portuguese entry into Indian Ocean commerce formalised some existing relations and rivalries of trade and force, and transformed others.11 The coercion used to police trading ports and routes was embodied in the Portuguese forts and citadels overshadowing harbour entrances. Many still survive. Conflict between the Portuguese and local merchants and rulers, and later between the Portuguese and the Dutch, reshaped the volumes of trade for cargoes traversing the sea. Spice became more important than other commodities and the routes that incorporated spice-producing lands became more profitable. Imperial monopoly restrictions on particular commodities encouraged new routes but also spelled the decline of many shorter, more local or coastal routes for products manufactured in India and Southeast Asia.
Under European control of trade in the Indian Ocean, and especially with British colonialism, ports were forced to specialise. Some primarily exported raw materials, while others became adept at producing specific manufactured goods. This process of specialisation affected what sorts of ships these ports could host and how well they were incorporated into imperial networks. New legal systems differentiated ports within the same imperium, allowing European powers to take advantage of variegations in sovereignty and a version of legal arbitrage. New monetary and credit regimes were introduced. Racialised hierarchies and various forms of exploitation of labour – from wage labour to corvée (or forced) labour, to indentured labour – were institutionalised by law.12 Sea routes, emporia of trade, and colonial bases were now affected by new modes of production. Colonial expansion ruthlessly decimated some ports and founded new nodes of trade in the region.
The production of knowledge about the empire was, from the first, a fiercely urgent need of the colonisers. Mapping both the sea and the land, oceanography, subsea topography, familiarity with the flora and fauna of the colonised ports, and ethnography all served the purpose of more effective colonisation and competition with imperial rivals. The Admiralty Charts that I had so admired were important tools for colonial powers. Long before they became a lucrative income stream for the British state through commercial sales, they were much coveted and jealously guarded sources of colonial knowledge. The men who invented new tools for navigation and the men who used them at sea became subjects of nationalist admiration.13 Colonial charts took routes defined by accidents of geography or topography or advantageous currents and winds, transformed