Steamships removed the message speed limit imposed by horses and sails, and telegraphy made communication almost instantaneous. Top state sizes expanded accordingly. Graphs superimpose the growth–decline curves of major post−1800 Engineer Empires. Britain became the largest empire ever (24% of world dry land area), but it lasted at more than half of its maximum size only for 110 years, comparable to nomad Xiongnu. State collapse in China also made Britain briefly the most populous of the world, due to its control of India. For most of the Engineer period Russia has been the largest and China (Qing and People’s Republic) the most populous. India’s population surpassed China’s in 2023. At the 1925 peak of European domination, 64% of Earth’s dry land area was ruled from Europe. It is now down to 21%, mainly Siberia. But European-stock Russia, USA, Canada, Brazil, and Australia remain part of the top seven, along with China and India. Population proportions differ. Since 1800, six to ten states have held more than 2% of Earth’s dry land area. Every half-century, three to four have entered or exited this category. By this pattern, 2000−2050 has been unusually quiet, up to now.

A graph superimposes the growth–decline curves of major Late Rider Empires, from 1200 to 1800. This was a period of shift from horses to sails. West European feudalism indirectly led to respect for law and a curiosity revolution. Inciting exploration, the latter began to give rise to transoceanic empires, first of all Spanish. But at first, Mongol horsemen seized a record-size area, unsurpassed among land-borne empires. Up to 1750 all truly large empires except Spanish remained land bound: Manchu Qing, Russia, Ottoman, and Mughal. The burgeoning French, Portuguese, and British empires were still modest. Much of the Mongol hold meant sparsely populated superficial tribute area, but by conquering China the Mongol empire also became the world’s most populous. Later on, Ming, Mughal, and Qing shared this eminence. Nomad empires were a phenomenon that rose and ended with the Rider phase. The Inca and Aztec empires retraced from scratch the human self-domestication process that the Old World underwent thirty-five centuries earlier, but they still lacked metals and the wheel.

This chapter introduces the book’s central puzzle, makes the case for considering Western imperialism through systematic comparison with its Asian predecessors and contemporaries, and previews the book’s central argument. I argue that the literature on international hierarchy and empires has neglected critical parallels between Western and Asian empire-building in the early modern period. Mughal, Manchu and British empire-builders each confronted significant barriers to conquest, in the form of cultural marginality and demographic insignificance relative to indigenous majorities. Each consequently relied on strategies of define and conquer and define and rule to mobilize the vast multicultural coalitions needed for large-scale territorial expansion. These parallels in turn yielded empires that foregrounded the management of cultural diversity – through the incorporation of difference rather than its assimilation – as the chief feature of imperial rule.

This chapter explains the Mughal and Qing empires’ diverging fates over the eighteenth century, owing to variations in their ability to accommodate cultural diversity over the course of territorial expansion. The Mughal Empire failed to extend its regime of syncretic incorporation as it expanded into the Deccan, prefiguring imperial overstretch, a legitimation crisis and subsequent decline. Conversely, the Manchus extended their diversity regime of segregated incorporation as they conquered vast new territories on the Eurasian steppe. The resulting divergence opened up opportunities for the East India Company’s later rise in India, even while continued Manchu dynamism limited Western expansion in mainland East Asia. The chapter proceeds as follows. The first section sketches the Mughal Empire’s fall, canvassing existing explanations for its decline, before advancing an alternative account in the second section. The third and fourth sections then respectively narrate and explain the Manchu Empire’s further expansion during the eighteenth century. The fifth section reviews the legacies of these empires’ divergent trajectories in shaping their respective regions’ subsequent evolution.