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 them through the political power of commerce, and ‘naturalised’ them again. The age of steam only reinforced the process.
Steamships changed the face of navigation and the pathways of trade. Ships were no longer bound to the seasons and winds. Even more important, the provision of fuel for oceangoing ships – first coal and, in the twentieth century, oil – spread the tentacles of empire to numerous ports around the world. The earliest steamships required vast amounts of coal and, when traversing open seas, their boilers encrusted with sedimented and corrosive salts and their inner machinery required all-too-frequent lubrication.14 But the navigability and power of steamships made them an irresistible weapon in the strategic and commercial contestation between European empires. The French colonisation of Algeria in 1830 stoked British fears that the Mediterranean was becoming a French lake in the same way the Black Sea had become a Russian lake. British imperial officials thought the consolidation of their control in South Asia could prove advantageous against France and Russia.15 But to reach South Asia profitably, more powerful, faster ships were needed.
The British East India Company’s conversion of its fleet to steamships in the 1830s marked the ascendance of steam, though it took decades before all the oceangoing ships rounding the Cape of Good Hope to India were converted. The East India Company’s turn to steam spurred the Government of Bombay to find a coaling station on the route from Bombay to Suez (and from there overland to Alexandria), resulting in the occupation of the island of Soqotra in the Indian Ocean in 1835. Soqotra’s harbours, however, did not provide good shelter, and the islands did not have the necessary infrastructure to support a coaling station. This led to the British abandoning Soqotra and bloodily conquering Aden in 1839. As a historian of the Suez Canal writes, Aden was ‘the first territorial acquisition of the Red Sea route and the first coaling station annexed to any empire’.16 The governor of Bombay, Sir Robert Grant, justified the conquest of Aden thus:
The establishment of a monthly communication by steam with the Red Sea, and the formation of a flotilla of armed steamers, renders it absolutely necessary that we should have a station of our own on the coast of Arabia, as we have in the Persian Gulf … As a coal depot, no place on the coast is so advantageous; it divides the distance between Bombay and Suez, and steamers may run into Back Bay during the night and unload at all seasons in perfect security.17
Distance and suitability as a halfway house went hand in hand with the possibilities both of trade and strategic access. Aden remained a fuelling outpost for the British Empire in the Indian Ocean even after petroleum displaced coal, until the British were driven out of Aden in 1967 by the anticolonial struggles there.
By the 1840s, the British Admiralty had also begun converting its naval vessels to steam, further intensifying the need for imperial coal depots. Between 1850 and 1869 alone, the net tonnage of British goods transported by steamships had increased from 168,474 to 948,367.18 Steamship technologies and imperial expansion were mutually reinforcing. The imperial steamships trading around, policing, and fighting upon the Indian Ocean required frequent and high-volume replenishment of their fuel coal. This, in turn, led to the conquest of new colonial beachheads along trade routes. These strategic outposts themselves generated additional trade, required a great deal more administrative information and communication, and necessitated more capital investment, more intensive exploitation of labour, and ever-expanding knowledge and intelligence about local conditions. In his account of the age of coal, On Barak explains the prevalence of British coal by the fact that products mined in Wales or Northern England could be exported to the colonies in ships that would otherwise have been in ballast (or not carrying cargo). The vast trade in British coal overseas encouraged industrialisation at home, while the rise of mass democracy in Europe resulting from the materialities of coal mining was accompanied by the projection of authoritarian power over colonies overseas.19
British control over much of the coastal areas in West, South, and East Africa translated into British supremacy over the Cape route to India. Britain also controlled the coal supplies, since ‘coal from Bengal was being used in steamers in the 1830s, from Borneo in the 1840s, and from Natal in the 1860s. Though not as good as Welsh coal, they gave Britain a near-monopoly of the world’s steamer coal supplies’.20 The opening of the Suez Canal in 1869 made Britain’s imperial coaling stations – and the routes that were strung between them – still more significant to Britain’s dominion over the oceans. Even as the British feared the French mastery in the Mediterranean and controlling shares in the Suez Canal, British primacy over the sea routes of the Red Sea, the
