This public lecture, the first in a 'What's New in Medieval' series co-sponsored by the Institute of Advanced Studies at UWA and the ARC Centre of Excellence for the History of Emotions, was delivered at The University of Western Australia on 18 April 2016. The lecture ranged selectively from the immediate post-medieval period to the present day, but with an emphasis on the period 1800-2000, and analysed long-term trends in the discourse of war in both high-culture and popular medievalism.