Yet the organizational edge which Byzantine forces had over their enemies was maintained well into the twelfth century, when the predominance of non- Byzantine mercenary forces becomes particularly clear. Attitudes also played an important part, and effective military organization owed something to the consciousness, not only of Byzantine military officers, but of civilians with no practical military experience as well, of a long and honourable tradition of military writing. This was in turn combined with the historical awareness, cultivated in the upper levels of literate Byzantine culture in both Constantinople and the provinces, of the past achievements of East Roman armies. But it was not just the knowledge of a catalogue of achievements. Much more importantly, the historical narratives and the military manuals offered reasons for these achievements: order, discipline and tactical cohesion in battle; well-planned logistical arrangements; and strict adherence to Orthodoxy and clear awareness of the crucial importance of divine support.
From Roman times on the values and the achievements associated with these characteristics are repeated time and again and, as we have seen, recur throughout Byzantine texts. And while it is clear that there were considerable periods when discipline, tactical order and competent field manoeuvres in combat situations were neglected, it is equally apparent that it was in particular the existence of this tradition of military writing and this sense of history which kept the precepts (and associated successes) of the writers of tactical and strategical treatises in mind, and which enabled commanders to revive, strengthen and enforce a code of military discipline, training and tactical skills.
The East Roman world was not alone in this element of literacy and historical consciousness, of course. The Islamic world, too, generated a complex, sophisticated and multi-faceted secular literary culture, in which the writing of military and tactical/strategical treatises also had a place; and from the twelfth century, western Europe began rapidly to evolve its own literary self- consciousness and awareness and to rival and overtake the East Roman world in organizational and technical structures. But it was this factor in combination with its particular political and administrative contours which differentiated East Roman culture from its neighbours until that time. As long as the central government was able to control and direct the resources to maintain the defensive arrangements appropriate to the situation, and as long as the strategic arrangements were equal to the international military and political context, East Roman armies were able to maintain, however precariously at times, an effective control over their own territories. And there can be no doubt that central control of this sort, however modified and occasionally weakened by circumstances, was maintained more consistently between the sixth and twelfth centuries in the Byzantine world than in the caliphate, which already by the second half of the ninth century was beginning to fragment politically and ideologically.