ABSTRACTThe British interest and presence in the South Atlantic Ocean and in South America represent, in the words of Eliga Gould, the kind of “entangled histories” increasingly recognised and studied by scholars of imperial, colonial and maritime history. From the beginning of the eighteenth century, the region was most frequently seen as the “key” to the Pacific Ocean. This paper, however, focuses on the place of this oceanic area, its islands and its coastal littorals in another “gateway zone”: the entrance to, and exit from, Britain's Indian Ocean world and the riches of Asia. The strategic location of various South Atlantic islands and South American colonial entrepôts played on the minds of politicians, policy-makers, publicists and merchants in London, as well as colonial governors and military commanders on station. Drawing on the archival riches of the East India Company, as well as primary published material such as pamphlets and prospectuses, this paper will explore the interaction of the Atlantic and Indian oceans at this maritime fault-line. The discussion will demonstrate, for example, how the “barren and rocky isle” of St Helena, “abandoned to a state of hopeless destitution in the solitude of the ocean,” could be regarded as an “essential part of the British Empire.” And similarly, it will demonstrate how places such as Montevideo, Rio de Janeiro and Tristan da Cunha were regarded in relation to the rising British Empire in Asia. More broadly, the region cannot be understood, this paper suggests, without considering the wider context of British imperial and commercial activity in the period and, more specifically, the growing importance of British trading and political interests in the East Indies.