Nineteenth Century novelists frequently picture life beyond and across the edges of humanity—figuratively moving the ‘posts’ of humanity—a practice that this article calls ‘posthumanisation’. Inspired by the accelerating as well as mutually reinforcing dynamics of colonial expansion, empiricism, new biological and scientific findings (Darwin, paleontology, and psychology), and the rise of industrialisation, prominent writers such as Mary Shelley, the Brontë sisters, and Joseph Conrad habitually blur human-animal boundaries. This article engages with versions of posthumanisation in selected novels by these authors—Mary Shelley’s Frankenstein (1818), Charlotte Brontë’s Jane Eyre (1847), and Joseph Conrad’s Heart of Darkness (1898)—and the anonymously published The Woman of Colour (1808), examining how they engage either in critiquing the perfidious overlaps between posthumanisation and colonial discourse ( The Woman of Colour; Frankenstein) or blur Cartesian binaries between humans and animals to reinforce colonialism’s narcissistic politics of non-relation (for example, see Gandhi, 2006; Simmons, 2007; and Drichel, 2018). The article foregrounds the extent to which a thriving colonial discourse and biological racism do not (necessarily) result in a ‘fixing’ of racial others on the side of ‘animal’ (and, as such, in their ‘dehumanisation’), but rather in a strategic ‘flexibilisation’ of ‘hum-animality’ (see Ellis, 2018) in the interest of plausibilising white supremacy and the slavery system. Arguing for the merit of historicizing literary analysis as posthumanist scholarship directs its gaze to the past; building on race-critical contributions to posthumanist discourse (see, for example, Malm and Hornborg, 2014; Jackson, 2015; Jackson, 2020; Davis et al., 2019; and Yussof, 2019); and also engaging with the still-scarce scholarship on the overlaps of posthuman being and race relations in the context of Britain’s ‘imperial century’ (see Ellis, 2018; and Jackson, 2020), this essay contributes to setting on a more solid, historical foundation a discourse that has repeatedly been criticised for engaging a ‘racial’ ‘wilful blindness’ ( Yusoff, 2018). The article thus contributes to diversifying not only historical approaches to ‘proto-posthumanisms’ as they are currently proliferating in the field but also, and by implication, current posthumanist self-understandings and research ethics.