 He had had a fleet built of over 1,000 ships at Samosata in order to supply his army for a march down the Euphrates and of 50 pontoon ships to facilitate river crossings.Procopius and the Armenians would march down the Tigris to meet Julian near Ctesiphon.Julian's ultimate aim seems to have been "regime change" by replacing king Shapur II with his brother Hormisdas.