direction of the confluence of the Tigris and the Diyala; the other commanded by Gobryas, the satrap of Gutium, followed the course of the Adhem or the Diyala, and brought the northern contingents to the rallying-place.  From what we know of the facts as a whole, it would appear that the besieging force chose the neighbourhood of the present Bagdad to make a breach in the fortifications.  Taking advantage of the months when the rivers were at their lowest, they drew off the water from the Diyala and the Tigris till they so reduced the level that they were able to cross on foot; they then cut their way through the ramparts on the left bank, and rapidly transported the bulk of their forces into the very centre of the enemy’s position.  The principal body of the Chaldaean troops were still at Opis, cut off from the capital; Cyrus fell upon them, overcame them on the banks of the Zalzallat in the early days of Tammuz, urging forward Gobryas meanwhile upon Babylon itself.* On the 14th of Tammuz, Nabonidus evacuated Sippar, which at once fell into the hands of the Persian outposts; on the 16th Gobryas entered Babylon without striking a blow, and Nabonidus surrendered himself a prisoner.**

* For the strategic interpretation of the events of this campaign I have generally adopted the explanations of Billerbeck.  Herodotus’ account with regard to the river Gyndes is probably a reminiscence of alterations made in the river-courses at the time of the attack in the direction of Bagdad.

** The Cylinder of Cyrus, 1. 17, expressly says so:  “Without combat or battle did Marduk make him enter Babylon,” The Annals of Nabonidus confirm this testimony of the official account.

The victorious army had received orders to avoid all excesses which would offend the people; they respected the property of the citizens and of the temples, placed a strong detachment around E-sagilla to protect it from plunder, and no armed soldier was allowed within the enclosure until the king’ had determined on the fate of the vanquished.  Cyrus arrived after a fortnight had elapsed, on the 3rd of March-esvan, and his first act was one of clemency.  He prohibited all pillage, granted mercy to the inhabitants, and entrusted the government of the city to Gobryas.  Bel-sharuzur, the son of Nabonidus, remained to be dealt with, and his energetic nature might have been the cause of serious difficulties had he been allowed an opportunity of rallying the last partisans of the dynasty around him.  Gobryas set out to attack him, and on the 11th of March-esvan succeeded in surprising and slaying him.  With him perished the last hope of the Chaldaeans, and the nobles and towns, still hesitating on what course to pursue, now vied with each other in their haste to tender submission.  The means of securing their good will, at all events for the moment, was clearly at hand, and it was used without any delay:  their gods were at once restored