trade route. However, the overall scarcity of manpower for the Roman military establishment meant that the campaign was doomed from the start. It is noteworthy that no new legions were raised by Trajan before the Parthian campaign, maybe because the sources of new citizen recruits were already over-exploited. As far as the sources allow a description of this campaign, it seems that one Roman division crossed the Tigris into Adiabene, sweeping south and capturing Adenystrae; a second followed the river south, capturing Babylon; Trajan himself sailed down the Euphrates from Dura-Europoswhere a triumphal arch was erected in his honourthrough Ozogardana, where he erected a "tribunal" still to be seen at the time of Julian the Apostate's campaigns in the same area. Having come to the narrow strip of land between the Euphrates and the Tigris, he then dragged his fleet overland into the Tigris, capturing Seleucia and finally the Parthian capital of Ctesiphon. He continued southward to the Persian Gulf, when, after escaping with his fleet a tidal bore on the Tigris, he received the submission of Athambelus, the ruler of Charax. He declared Babylon a new province of the Empire and had his statue erected on the shore of the Persian Gulf, after which he sent the Senate a laurelled letter declaring the war to be at a close and bemoaning that he was too old to go on any further and repeat the conquests of Alexander the Great. Since Charax was a de facto independent kingdom whose connections to Palmyra were described above, Trajan's bid for the Persian Gulf may have coincided with Palmyrene interests in the region. Another hypothesis is that the rulers of Charax had expansionist designs on Parthian Babylon, giving them a rationale for alliance with Trajan. The Parthian city of Susa was apparently also occupied by the Romans. According to late literary sources (not backed by numismatic or inscriptional evidence) a province of Assyria was also proclaimed, apparently covering the territory of Adiabene. Some measures seem to have been considered regarding the fiscal administration of Indian tradeor simply about the payment of customs (portoria) on goods traded on the Euphrates and Tigris. It is possible that it was this "streamlining" of the administration of the newly conquered lands according to the standard pattern of Roman provincial administration in tax collecting, requisitions and the handling of local potentates' prerogatives, that triggered later resistance against Trajan.