Zosimus, New History 2.30
Zosimus (Greek Ζώσιμος): Early Byzantine, pagan author of a history of the Roman Empire, published in the first quarter of the sixth century CE.
The translation of Zosimus' New History offered here was printed in 1814 by W. Green and T. Chaplin in London, and was probably prepared by J. Davis of the Military Chronicle and Military Classics Office. The translator is anonymous. The text was found at Tertullian.org. The notes were added by Jona Lendering.
[2.30.1] Being unable to endure the curses of almost the whole city, he sought for another city as large as Rome, where he might build himself a palace. Having, therefore, discovered a convenient scite between Troas and old Ilium, he there accordingly laid a foundation, and built part of a wall to a considerable height, which may still be seen by any that sail towards the Hellespont. Afterwards changing his purpose, he left his work unfinished, and went to Byzantium,
[2.30.2] where he admired the situation of the place, and therefore resolved, when he had considerably enlarged it, to make it a residence worthy of an emperor. The city stands on a rising ground, which is part of the isthmus inclosed on each side by the Golden Horn and Propontis, two arms of the sea. It had formerly a gate, at the end of the porticos, which the emperor Severus built after he was reconciled to the Byzantines, who had provoked his resentment by admiting his enemy Niger into their city.
[2.30.3] At that time the wall reached down from the west side of the hill at the temple of Venus to the sea side, opposite to Chrysopolis. On the north side of the hill it reached to the dock, and beyond that to the shore, which lies opposite the passage into the Euxine Sea. This narrow neck of land, between there and the Pontus,note is nearly three hundred stadia in length.
[2.30.4] This was the extent of the old city. Constantine built a circular market-place where the old gate had stood, and surrounded it with double roofed porticos, erecting two great arches of Praeconnesian marble against each other, through which was a passage into the porticos of Severus, and out of the old city. Intending to increase the magnitude of the city, he surrounded it with a wall which was fifteen stadia beyond the former, and inclosed all the isthmus from sea to sea.