It would have been 24 August 410 A.D. Had you been hunting or fishing on that day, perhaps, at the very northern edges of the Empire, you would have been distracted by an ominous vibration beneath your feet. An earthquake? You put your ear to the ground. No. it is not an earthquake. This is herd movement, a massive stampede across the northern hinterlands like you have never sensed before or after. How did W.H. Auden conclude his brilliant poem (1951), The Fall of Rome