Beate Dignas & Engelbert Winter - Kaveh Farrokh

206 6 Shared interests: Continuing conflicts
year 422, very close in time to the foedus between Bahrām V Gōr and
Theodosius II (19), an edict was issued according to which trade between
the two empires was permitted only in places that had been designated
in earlier constitutions. 172 Attempts to circumvent the official regulations
of 408/9 may have triggered new legislation and a confirmation of their
content. 173 This corresponds with the warning not to host foreign merchants
without the knowledge and consent of the comes commerciorum,
which was issued at the same time. 174 Finally, three articles of the elaborate
treaty concluded between Xusrō I Anōˇsarvān and Justinian I in 562 (20)
addressed decisions regarding economy and trade. These adhered to the
general guidelines that had already been fixed in 298 and 408/9 and that
remained valid until the end of the Byzantine–Sasanian relations in the
early seventh century. The economic rivalry between Byzantium and Persia
continued in spite of the peace. However, the increasing hostilities, in particular
the Sasanian offensives at the beginning of the seventh century (15), no
longer allowed for a regulated and uninterrupted flow of trade between both
states.
The following conclusions may be drawn: from the end of the third
century onwards economic aspects also guided the diplomatic interaction
between the two empires. Attempts to deal with economic questions led
to political contacts. 175 Trade related interests, above all the assessment of
customs duties, gained more and more significance as they both intensified
contacts and increased rivalries. Given the increasing ideological and
military tensions between the empires a free exchange of goods without
state intervention and control ceased to exist. In contrast to their predecessors,
the Sasanian kings did not accept any Roman superiority but
pursued an active expansionist foreign policy; with the treaty of 298 (17)
Diocletian reacted to this by introducing a policy that linked foreign trade
with Rome’s security. This policy became characteristic for the economic
relations between (East-) Rome and Persia.
Numerous constitutions and treaties confirm a consistent policy on
both sides, always accompanied by Roman attempts to establish multiple
alliances with the prospect of creating new trade routes by land and
by sea that would avoid Sasanian territory. 176 According to the Byzantine
historian Menander Protector the start of diplomatic relations between
172 Cod. Iust. iv.63.6. praef.; cf. also De Laet 1949: 458–9 and Karayannopoulos 1958: 167.
173 Karayannopoulos 1958: 160–1.
174 Cod. Iust. iv.63.6, praef.
175 On the shared economic interests of the great powers see also Frye 1972: 265–9.
176 In this context cf. esp. Pigulevskaja 1969; also Eadie 1989: 113–20; Sidebotham 1989: 485–509 and
1986a: 16–36 and 1986b.