Caught between the expanding frontiers of the Indian Ocean slave trade from the east and Afro-Portuguese slavers from the West, late nineteenth-century Katanga was a site of great social flux. Preexisting identities were broken and remade or profoundly challenged by the appearance of new polities such as those of Tippu Tip, Msiri or the Batetela. A few decades later, when colonialism had introduced another new polity, identities and their spatial frames of reference again needed redefinition. The paper examines the role of returned ex- slave diaspora in formation of Christian and ethnic identities amongst the Luba speaking peoples of Katanga. Taken from their homes by Ovimbundu slavers in the 1870-1900s these Luba returnees had been Christianised while laboring on plantations in Bié, Angola. The article examines how the spatial experience of dislocation and expanded horizons provided the vital backdrop to the Luba slaves’ conversion. It explores how they made sense of their experience in terms of the narratives of exodus, exile and return in the Hebrew Scriptures and how the notion of a chosen people formed the basis of a supra-local vision upon which a Luba ethnic consciousness would be founded. They returned in the 1910s, seeing themselves as missionaries of a Christian modernity. From initially fairly isolated missionary settlements they combined local attachment in their areas of origin with long-distance mobility and Christian connectedness. They thus acted as ethnic enthusiasts, spreading Luba identity by means of literacy, schooling and new vernacular scriptures.