VI. The Romans had a fort by the side of the river Euphrates on the extreme frontier of Mesopotamia, at the place where the river Aborrhas[41] effects its junction with the Euphrates. This fort was named Circesium,[42] and had been built in former times by the Emperor Diocletian; however, our present Emperor Justinian, finding that it had become ruinous through lapse of time, and was neglected and not in a posture of defence, altered it into a strong fortification, and made it into a city of eminent size and beauty. When Diocletian built the fort he did not completely surround it with a wall, but brought each end of the walls down to the river Euphrates, built a tower at each end of them, and left the side between them entirely unfortified, imagining, I suppose, that the waters of the river would suffice to defend the fort on that side. In the course of time, however, the stream of the river, continually eating away the bank, undermined the tower on the south side, and it became evident that unless prompt measures were taken it would shortly fall. Now appeared the Emperor Justinian, entrusted by Heaven with the glory of watching over, and, as far as one man can do, of restoring the Roman Empire. He not only saved the undermined tower, which he rebuilt of a hard stone, but also enclosed all the unprotected side of the fort with a very strong wall, thus doubling its security by adding the strength which it derived from the wall to that afforded by the river. Besides this, he also built a powerful outwork round the city, especially at the spot where the junction of the two rivers forms a triangular space, and thus left no place exposed to the attacks of the enemy. Moreover, he appointed a general who had the title of Duke, and who always resided there with a garrison of picked soldiers, thus rendering the place a sufficient bulwark for the frontier of the empire. He also rebuilt in its present splendour the public bath which is used by the inhabitants, which had become quite ruinous and useless by the incursions of the river; for he found all that part of it which is suspended above the solid foundation for the convenience of bathers, underneath which the fire is placed, and which is called the hypocaust, exposed to the influx of the river, by which the bath was rendered useless; he therefore strengthened with stonework, as I have said, the part which formerly had been hollow, and built another hypocaust above it, which the river could not reach, thus restoring the enjoyment of the bath to the garrison. In this manner did our Emperor restore the buildings of Circesium.