Using the lens of the cattle frontier in Madagascar in the late nineteenth and twentieth centuries, this project explores the transformation of livestock production, pastoralist societies, imperial economies and animal landscapes in colonial and postcolonial Africa. It builds on the concept of commodity frontiers, moving sites of capitalist commodity production and extraction, to disentangle the complex interplay between global capitalism, science and empire in the making and unmaking of the cattle frontier in Madagascar. COLCAT examines why and how European (mostly French) and Malagasy administrators, entrepreneurs and veterinary experts, in often conflictual interaction with indigenous pastoralists, tried to transform pre-existing cattle economies on the island and to turn cattle into profitable commodities. It argues that the making of a capitalist and imperial cattle frontier implied a broad range of interventions, from the improvement of local breeds and new methods of cattle disease management to the sedentarisation of cattle pastoralists and the establishment of meat factories and new cattle trading networks. COLCAT analyses the rationales and dynamics of these interventions, including the manifold conflicts, negotiation processes and (intended and unintended) social, economic and ecological consequences. It thereby pays particular attention to the role of science and expert knowledge.  While COLCAT’s main focus is on the profound transformations of the colonial era (1895-1960), it embeds them in a longue-durée perspective, spanning late Merina rule in the precolonial period (1870-95) to the postcolonial era (1960-80). This will facilitate teasing out the tensions between capitalist, imperial and (post)colonial expansion and development goals. Overall, COLCAT will make a substantial contribution to the history of global capitalism, the history of (French) colonialism in Africa, environmental history and the history of science and knowledge.