Chapter 1 introduces the book’s aims and scope. It traces the origins and contexts of Britain’s desire for rehabilitation of the Empire in the age of reform and, especially, its plans in the post-abolition era to protect indigenous rights by improving the reach and influence of British law on colonial frontiers. This concern to protect indigenous people through legal reach aligned with older understandings of protection as a mechanism for asserting imperial jurisdiction in distant colonial settings, and it expanded upon a centuries-old imperial history of protection offices. The chapter situates the history of ‘Aboriginal protection’ within this longer imperial context, as well as within the wider context of protection policies that developed around the nineteenth-century British Empire to regulate relations with slaves, Indian indentured labourers, diasporic Chinese communities and others. Whether applied to slaves, indigenous people, indentured labourers or other mobile diasporas, Protectors as government officials oversaw both the rights and the obligations of colonial subjecthood.