The impatience of Julian scarcely allowed him to await the conclusion of the winter.  With the first breath of spring he put his forces in motion, and, quitting Antioch, marched with all speed to the Euphrates.  Passing Litarbi, and then Hiapolis, he crossed the river by a bridge of boats in the vicinity that place, and proceeded by Batnee to the important city of Carrhae, once the home of Abraham.  Here he halted for a few days and finally fixed his plans.  It was by this time well known to the Romans that there were two, and two only, convenient roads whereby Southern Mesopotamia was to be reached, one along the line of the Mons Masius to the Tigris, and then along the banks of that stream, the other down the valley of the Euphrates to the great alluvial plain on the lower course of the rivers.  Julian had, perhaps, hitherto doubted which line he should follow in person.  The first had been preferred by Alexander and by Trajan, the second by the younger Cyrus, by Avidius Cassius, and by Severus.  Both lines were fairly practicable; but that of the Tigris was circuitous, and its free employment was only possible under the condition of Armenia being certainly friendly.  If Julian had cause to suspect, as it is probable that he had, the fidelity oL the Armenians, he may have felt that there was one line only which he could with prudence pursue.  He might send a subsidiary force by the doubtful route which could advance to his aid if matters went favorably, or remain on the defensive if they assumed a threatening aspect; but his own grand attack must be by the other.  Accordingly he divided his forces.  Committing a body of troops, which is variously estimated at from 18,000 to 30,000, into the hands of Procopius, a connection of his own, and Sebastian, Duke of Egypt, with orders that they should proceed by way of the Mons Masius to Armenia, and, uniting themselves with the forces of Arsaces, invade Northern Media, ravage it, and then join him before Ctesiphon by the line of the Tigris, he reserved for himself and for his main army the shorter and more open route down the valley of the Euphrates.  Leaving Carrhae on the 26th of March, after about a week’s stay, he marched southward, at the head of 65,000 men, by Davana and along the course of the Belik, to Callinicus or Nicophorium, near the junction of the Belik with the Euphrates.  Here the Saracen chiefs came and made their submission, and were graciously received by the emperor, to whom they presented a crown of gold.  At the same time the fleet made its appearance, numbering at least 1100 vessels, of which fifty were ships of war, fifty prepared to serve as pontoons, and the remaining thousand, transports laden with provisions, weapons, and military engines.