East Roman military administration remained, until the twelfth century, far in advance of that of its nearest neighbours, even though that of the Muslim states and principalities to the east was also very sophisticated. But the continued centralization of fiscal structures and consequent control over resources in materials and men (both politically and economically) gave the Byzantine government an advantage which none of its foes enjoyed. As long as the central government maintained its grip on the tax-extracting (or resource- extracting) machinery of the state, it was able to direct resources according to the requirements of defence or offence, and in accordance with the overall interests of the empire, to the best effect, in theory if not always in practice. Efficacious use of resources in men and materiel depended, of course, on those in authority recognizing where the priorities lay and not having to fight for their point of view to be implemented. That this was not always the case the political history of the Byzantine empire all too frequently shows.