After the capture of Ctesiphon the Emperor set sail down the Tigris with a fleet of fifty ships, among them the large, clumsy imperial galley, elaborately decorated, upon which he expected to hold conferences en route.[1] Various cities of Mesene were occupied, including Akra or Agra beyond the Tigris,[2] Oratha,[3] and an Apamea[4] where the Tigris divided, the branch to the left being the true Tigris and the other the Selas.[5] Attambelus V of Characene remained faithful to Trajan, even though ordered to pay tribute.[6] Perhaps a statue was erected to the Emperor on the shore of the Persian Gulf.[7]
On the return trip Trajan passed Borsippa (Birs Nimrud) and then stopped at Babylon, where he sacrificed in the room in which Alexander was reputed to have died.[8] This trip to the Gulf must have occupied the winter of 115/16. While at Babylon in the early spring of 116 Trajan learned that most of the conquered territory had revolted and massacred or expelled the garrisons left there. The Romans were apparently caught without warning, probably because of inadequate intelligence service. Jerome's remark, written about two hundred and fifty years
