Beyond Circesium there is an ancient fort named Annucas, whose wall the Emperor Justinian found a mere ruin, and which he rebuilt in so magnificent a fashion that its defences vie with those of the most celebrated cities; and in the same manner he rendered formidable, and altogether unapproachable by an enemy, those forts situated near the city of Theodosiopolis, which before his time were either without walls, or only walled with mud and absurd heaps of stones. These are Magdalathum, with two others on either side of it, and the two forts, the Great and Little Thannurium, Bismideon, Themeres, Bidamas, Dausaron, Thiolla, Philæ, Zamarthas, and, one may say, all the rest. There was an extensive position near Thannurium, which could easily be occupied by our enemies the Saracens, by crossing the river Aborrhas, from which point they were able to penetrate in small parties into the thick and extensive forest and the mountain which is situated in that region, and make inroads upon the Roman inhabitants of that country; now, however, the Emperor Justinian has built a tower of hard stone in that place, manned it with a considerable garrison, and has altogether repressed the incursions of the enemy by the establishment of this bulwark against them. VII. The above are the works of the Emperor Justinian in this part of Mesopotamia; I must speak in this place of Edessa, Carrhæ, Callinicum, and all the other strong places which are in that country, since they lie between the two rivers. Edessa[43] stands on the banks of a small stream called Scirtus, which collects its waters from many places, and runs through the midst of the city: from thence it passes onwards, after having supplied the wants of the city, effecting its entrance and exit through by a channel constructed by former generations, which passes through the city walls. This river once, after much rain, rose to a great height, and seemed as though it would destroy the city; it tore down a large part of the outworks and of the walls, inundated almost the whole city, and did much damage, suddenly destroying the finest buildings, and drowning a third part of the inhabitants. The Emperor Justinian not only at once restored all the buildings of the city which were overthrown, among which were the church of the Christians and a building called Antiphorus, but also arranged with great care that no such disaster should ever again occur, for he made a new channel for the river, outside the city walls, which he arranged in the following manner. The ground on the right bank of the river was formerly flat and low-lying, while that on the left was a precipitous mountain, which did not allow the river to turn aside from its accustomed course, but forced it to flow into the city, because when flowing towards the city it met with no obstacle on its right bank. He therefore dug away the whole of this mountain, making a channel on the left bank of the river deeper than its former bed, and built on