At the end of the nineteenth century, settler states gained implicit imperial sanction to practice racialised border-policing on disingenuous grounds of language proficiency. As is well known, this outcome was the result of settler dominion efforts through the late nineteenth century to consolidate ‘whiteness’ as the structuring principle of future settler nationhood. But the pathway to this outcome was neither smooth nor inexorable: it emerged from an interconnected colonial world that was inherently multiracial and unsettled. Although the nineteenth-century experiment of settler colonisation was dominated by British migrants motivated by land ownership, the settler colonies were also occupied by a diverse mix of non-European people on the move. Their contributions formed an essential underpinning of settler colonial growth in ways that highlighted Australia’s dependency on broader patterns of colonial trade and migration around and beyond the empire. Of the ethnically diverse peoples who migrated to colonial Australia, some were already British subjects; others were not. But a great many became permanent settlers who asserted their own understandings of citizenship in empire.