Perhaps the most striking feature of Britain's global expansion was the limited influence exerted over its course by the imperial government in London. Most of the energy behind British expansion was private, not public. Of course, it was true that it usually needed a mixture of private and public resources: capital, manpower, but also protection against external and sometimes internal opponents. Governments could withhold that protection and refuse to annex when the political risks they entailed seemed out of proportion. They could also strike bargains with rival imperialists that frustrated the plans of British settlers, merchants or missionaries. But only up to a point. The promoters of British expansion could usually mobilise both public and private ‘investment’ at home (both material and emotional), and use it to leverage additional resources on the local or colonial ‘spot’. It was this combination that made them so versatile; and that versatility was what made the British presence so ubiquitous.

The result by the later nineteenth century was the creation of a British world-system. Its system-like character can be seen in two ways. First, private and public activity had combined (most visibly in the strategic and technological achievement of long-distance sea-lanes) to encourage the growth of a single vast network centred on Britain, to distribute credit, capital, goods, information, manpower and protection on a global basis, and not into a set of closed ‘mercantilist’ zones each with its own rules.