I have been reading Hugh Trevor-Roper’s Wartime Journals (ed. Richard Davenport-Hines, London 2012): in fact more of an autobiographical commonplace-book or collection of pensées. Here is one entry from 1940/41 – written when he was working for the intelligence services from an office in Wormwood Scrubs (p. 39-40):
At a crisis in the history of Rome, to ease the pressure, the authorities commanded all professors to leave the beleaguered city, but kept back a large number of chorus girls. This seems like a reasonable measure to provide for the necessary refreshment of the defending troops; but since history is more often written by professors than by chorus girls, it has been most unfairly condemned.
The ultimate source of the story is clearly Ammianus Marcellinus’ first Roman digression (14.6.19):
Postremo ad id indignitatis est uentum,/ ut cum peregrini ob formidatam haut ita dudum alimentorum inopiam/ pellerentur ab urbe praecipites,/ sectatoribus disciplinarum liberalium impendio paucis/ sine respiratione ulla extrusis,/ tenerentur mimarum asseculae/ ueri, quique id simularunt ad tempus,/ et tria milia saltatricum/ ne interpellata quidem cum choris/ totidemque remanerent magistris.
Lastly things have reached such a pitch of unseemliness that, when quite recently foreigners were driven headlong from the city on the grounds of a feared shortage of provisions, devotees of the liberal arts, who were very few in number, were bundled out with no breathing-space, but mime-artists’ attendants were kept on (both the real ones and those who pretended to be temporarily), and three thousand dancers stayed behind without even being interrupted, along with their choruses and the same number of trainers.
The situation is not wartime but a food shortage in the year 383 or 384. What prompted this garbled version of Ammianus’ anecdote? Trevor-Roper is most unlikely to have encountered Ammianus' history in the Classical syllabus that he had studied at Oxford before changing to early modern history, or in his abundant reading beyond the syllabus. The source is surely his favourite prose model, Gibbon, misremembered. Chapter 31 of the Decline and Fall contains a brilliant adaptation of Ammianus' two Roman digressions, in order to ‘produce an authentic state of Rome and its inhabitants which is more peculiarly applicable to the period of the Gothic invasions’. The passage is reworked not within Gibbon’s paraphrase of Ammianus but a page or two later:
…the vast and magnificent theatres of Rome were filled by three thousand female dancers, and by three thousand singers, with the masters of the respective choruses. Such was the popular favour which they enjoyed, that, in a time of scarcity, when all strangers were banished from the city, the merit of contributing to the public pleasures exempted them from a law which was strictly executed against the professors of the liberal arts.
It was the mildly anachronistic placement of the passage in Gibbon immediately before the sack of Rome by the Goths that spurred Trevor-Roper to adapt the passage to his own situation: a cynical young Oxford don, full of contempt for professors (who are not of course the same as Ammianus’ sectatores of the liberal arts); in an imperial capital in a desperate state of siege by a Germanic foe; when all the London universities had in fact been evacuated – and chorus girls had not.