 After feigning a march further eastward, Julian's army turned south to Circesium at the confluence of the Abora (Khabur) and the Euphrates arriving at the beginning of April.Passing Dura on April 6, the army made good progress, bypassing towns after negotiations or besieging those which chose to oppose him.At the end of April the Romans captured the fortress of Pirisabora, which guarded the canal approach from the Euphrates to Ctesiphon on the Tigris.