This chapter investigates the bio-geographical imaginations behind the animal 'back-breeding' programs carried out by Lutz and Heinz Heck - two influential German zoologists who ran Berlin and Munich zoos. Partly with close connections to and patronage from the National Socialist elite, the Heck brothers sought to resurrect the wild cow (aurochs) and horse (tarpan) by breeding out the degeneration they associated with domestication. These back-bred animals were released during the war to roam the expanding territory of the Third Reich, and figured in propaganda films and newspaper articles legitimating that expansion. Drawing on archive material, this chapter situates these back-breeding initiatives in relation to the emerging field of geopolitics. It traces how the project to recreate extinct primordial wildlife functioned as part of discourses and practices of nature conservation that emphasized the ideal Germanic character of the European landscape and required ethnic cleansing as a form of ecological restoration. The chapter describes how back breeding of primordial wildlife was part of a legitimation of the violent Eastern expansion, emanating from a particular combination of mythological, geographic and ecological imaginations, not merely aiming for industrial and agricultural autarky but also to extend the Nazi governance of landscape conservation.