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.