This thesis is a history of the making of extradition law in early colonial Hong Kong. It explains extradition as a doctrinal product of British jurisdictional practice following the assumption of sovereignty over Hong Kong and against the backdrop of a new treaty relation with China. The rules of extradition were not consciously invented as such, but slowly and indirectly shaped as British officials contended with their complex treaty rights and obligations. Of special concern were enduring uncertainties over criminal jurisdiction. Contrary to traditional accounts, British legal imperialism in China was not characterised simply by the imposition of unreciprocated ‘extraterritoriality’. Instead, bilateral debates as well as discussions within British officialdom revolved around whether criminal jurisdiction ought to be demarcated according to territory, nationality, or a combination of the two. Nothing was presumed without extended negotiation and policy experimentation. As the only formal British colony in the area, Hong Kong became the focal point of such jurisdictional manoeuvring. In and around Hong Kong, the exigencies of diplomacy, colonial rule, and imperial ordering coalesced to give shape and significance to extradition, as distinct from other mechanisms of structuring criminal jurisdiction. At the same time, the political character of Hong Kong was enunciated. The territory came to be perceived as a beneficiary of humane and protective colonial rule—a beacon of British liberty, standing in proud opposition to Chinese despotism, but also a place where no criminal would find refuge. It was in this way that the colony and its law evolved, side by side, out of a primordial soup of jurisdictional plurality.