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.
The geographical situation of the empire offered, in this respect, both disadvantages and advantages. In the former case, the fact that potentially hostile powers were to be found on at least two, and usually three, fronts (Balkan, Syrian/Anatolian and maritime) meant that resources were always spread very thinly. In the latter, the mountain ranges which protected the Anatolian territories of the empire, together with the associated climatic conditions, appear to have discouraged attempts from the Arab Islamic powers to the south to occupy the areas beyond the Taurus-Anti-Taurus frontier zone, except very occasionally and, ultimately, unsuccessfully. And even when fortresses on the Byzantine side of this zone were seized and occupied, the Byzantine riposte was usually rapid and effective, inhibiting any longer-term build-up of military strength on the part of the invaders. In the Balkans, the situation was by no means so clear cut, but on the other hand neither the empire nor its closest powerful neighbour, the Bulgar state, enjoyed a natural boundary (until the empire extinguished Bulgar independence and recovered control of the regions up to the Danube in the late tenth century), and the political imbalance between the two was never as marked as between the Umayyad and Abbasid caliphates at the height of their power (c. AD 660–740 and 780–840) and the empire.