This is an article I never thought I’d write, from a viewpoint I never thought I’d have. Being nerdy about historical music and instruments, I’ve been one of those people who have tutted and rolled my eyes in dismay when historical anomalies, inaccuracies and impossibilities appear in historical films and novels. I’ve played small parts in such films myself, playing historical music. My role as musician in one TV series marked my transformation from annoyed nerd to a more informed person about the multiple processes involved in creating such dramas, and the necessity of putting complete accuracy aside. This article explains how and why, and my realisation of the truth that everyone involved in living history is choosy about which parts we re-enact and which aspects of modernity we’d rather keep. As I’ll show, the same is necessarily true of film-makers, for more complex reasons.