The question of the quantities of grain the army required for its soldiers and livestock is complicated by several factors, in addition to a relative sparseness of detailed statistical evidence, especially from the middle Byzantine period. In particular, the values of the weights and measures used in Byzantine texts, as well as the more detailed and informative material from the late Roman period and before, are still by no means generally agreed. In addition, the technology of milling and baking, and the types of grains involved, present several problems. I have assumed in respect of the figures which are given in the sources that they refer to unmilled grains, except in one or two cases where flour is actually stated to have been supplied. In general, flour would be too easily damaged by weather and transportation, and the assumption in some texts that handmills were taken would tend to confirm this. In the following section, I have attempted briefly to survey the evidence for this aspect of military undertakings in order to provide a basis for calculations about the relationship between the needs and rate of consumption of the army, on the one hand, and the distances covered and duration of marches on the other.
As noted in Chapter 5, soldiers were issued with, or themselves milled and baked, two main varieties of bread: simple baked loaves, and double-baked “hard tack”, referred to in late Roman times as bucellatum and by the Byzantines as paximadion or paximation. The hard tack kept better and much longer, was easily produced in field conditions, and required a relatively unsophisticated milling and baking technique. 1 Hard tack could be baked either in field ovens—klibanoi—or simply laid in the ashes of camp-fires: the latter technique was no doubt employed when speed of movement was a priority, as the tenth-century Sylloge tacticorum specifies. 2
One document states clearly that 80 Roman pounds of “dry” bread (i.e. 25.6 kg/56.3 lb) could be baked from 1 artaba of wheat. 3 One artaba of wheat is the