284–c. 400 (GENERAL)

Diocletian: Fiscal administration

The physical production of coin was, throughout the later Roman and Byzantine period, an integral function of one of the several major fiscal institutions of the empire, and it is therefore to the organisational structure and development of those institutions that attention has first to be paid.

The fiscal administration of the later Roman and early Byzantine period was dominated by three institutions: the praetorian prefecture (praefectura praetorio), and the palatine ministries (comitivae) of the sacrae largitiones (‘ sacred largesses’) and res privata (perhaps best translated as ‘privy purse’). These institutions were theoretically, and for much of the period effectively, separate and independent, and although their nomenclature together with that of some of their officers, and the balance between them, were both subject to adjustment and development, the pattern and emphasis of their organisational structure remained comparatively stable.

Of these three institutions, all instruments of both revenue and expenditure, the praetorian prefecture, deprived almost entirely of military competence and reduced to fiscal and juridical functions by Constantine, was the most significant and indeed increasingly predominant. Given its recent history and remaining functions this was probably inevitable. The precise course of events remains uncertain, but in general it seems clear that as the coinage system, in terms of which the government had first calculated is fiscal needs and then collected and spent its revenue, had depreciated and finally disintegrated during the second half of the third century, so there had developed a consequent and marked tendency to transfer to a fiscal system based upon assessment, revenue and expenditure in kind.