I would like to begin my talk today with sincere thanks to De Re Militari and the Society for Military History, and in particular to Kelly DeVries, for inviting me to give this year's Journal of Medieval Military History Lecture. This series of lectures and the other military history sessions at Kalamazoo have for years brought together on a regular basis some of the most active medieval military historians, who constitute an enthusiastic and very discerning audience. I am honored and happy to have this opportunity to speak to such a group.

Although I spent my early years as a professional scholar studying late antique and early medieval history, I learned an important lesson that is still relevant to my current work on chivalry and the culture of late medieval warriors: old sources deserve a new look every once in a while. When I was a graduate student, Walter Goffart urged me to look at the Chronica Minora of the fourth through seventh centuries, and “see what there was in them.” These minor chronicles had not exactly been neglected in the previous five centuries of scholarship, but most of the work had been devoted to reconstructing authoritative but lost sources, many of them hypothetical, from bare-bones chronicle accounts. The great hope of editors and critics of the nineteenth century had been that diligent work on these sources would allow us to understand what really happened to the Roman Empire after A.D. 400.