Book 31 of the Res Gestae describes events from 376 to early autumn 378, focussing almost exclusively on events in the Eastern half of the empire. The main focus of the volume is on the Gothic invasion of the empire resulting in the defeat of the Roman army and the death of the emperor Valens at the battle of Hadrianopolis on 9 August 378. Perhaps one of the most remarkable features of this volume is that although the authors wrote at a time when over a million migrants were streaming almost unchecked into Europe across borders that were suddenly revealed to be as permeable and ill-defended as the Danube frontier in 376, they never once allude to this fact. There are no simplistic comparisons and no virtue-signalling, so that one is left entirely ignorant of their political beliefs. In this, and in other matters, the authors reveal awareness that they are writing a timeless monument of scholarship for all posterity, not a fashionable opinion piece to be discarded next year: no brownie points gained here for outraged attacks on the discomfiting views of Niall Ferguson. Such restraint is entirely commendable.