A conversation with Nathan Aschenbrenner (Bard College) about western European claims to the Roman imperial title, from the Middle Ages to early modernity. We also discuss some plans in the west after 1453 to reclaim the "eastern empire" and a curious history from the early sixteenth that fuses western and eastern imperial history into one. Nathan (along with Jake Ransohoff, episode no. 83) co-edited the volume The Invention of Byzantium in Early Modern Europe (Dumbarton Oaks 2021).