Some idea of the appearance of the quays may be gathered from the right-hand corner of the restoration in Fig. 5.[55] It is true that the outer quay-wall appears to have been built to replace the inner one, while in the illustration both are shown. But since the height of the citadel and of its walls was continually being raised, the arrangement there suggested is by no means impossible. But in the later part of his reign Nebuchadnezzar changed the aspect of the river-front entirely. To the west of the quay-walls, in the bed of the river, he threw out a massive fortification with immensely thick walls, from twenty to twenty-five metres in breadth.[56] It was constructed entirely of burnt-brick and bitumen, and, from his reference to it in an inscription from Sippar, it would seem that his object in building it was to prevent the formation of sandbanks in the river, which in the past may have caused the flooding of the left bank above E-Sagila.[57] A narrow channel[58] was left between it and the old quay, along which the river water continued to flow through gratings. This no doubt acted as an overflow for the old northern moat of the citadel, since the latter fed the supply-canal, which passed round the palace and may still be traced along its south side.[59] It is possible that the subsequent change in the course of the Euphrates may be traced in part to this huge river-fortification. Its massive structure suggests that it had to withstand considerable water-pressure, and it may well have increased any tendency of the stream to break away eastward. However that may be, it is certain that for a considerable time during the Persian and Seleucid periods it flowed round to the eastward of the Ḳaṣr, close under three sides of the citadel and rejoined its former bed to the north of Marduk's temple and the Tower of Babylon. Its course east of the Ishtar Gate is marked by a late embankment sloping outwards, which supported the thicker of the crude-brick walls at the point where they suddenly break off.[60] Beyond this embankment only mud and river sediment were found. The water-course to the south of the citadel is probably the point where the river turned again towards the channel it had deserted. A trench that was dug here showed that the present soil is formed of silt deposited by water, and beyond the remains of the earlier canal no trace of any building was recovered. This temporary change in the river's course, which the excavations have definitely proved, explains another puzzle presented by the classical tradition—the striking discrepancy between the actual position of the principal ruins of Babylon in relation to the river and their recorded position in the Persian period. Herodotus,[61] for example, places the fortress with the palace of the kings (that is, the Ḳaṣr), on the opposite bank to the sacred precinct of Zeus Belus (that is, E-temen-anki, the Tower of Babylon). But we have now obtained proof that they were separated at that time by the Euphrates, until the river returned to its former and present bed, probably before the close of the Seleucid period.

The greater part of the Southern Citadel is occupied by the enormous palace on which Nebuchadnezzar lavished his energies during so many years of his reign. On ascending the throne of Babylon, he found the ancient fortress a very different place to the huge structure he bequeathed to his successors. He had lived there in his father's life-time, but Nabopolassar had been content with a comparatively modest dwelling. And when his son, flushed with his victory over the hosts of Egypt, returned to Babylon to take the hands of Bêl, he began to plan a palace that should be worthy of the empire he had secured. Of the old palace of Nabopolassar, in which at first he was obliged to dwell, very little now remains. What is left of it constitutes the earliest building of which traces now exist within the palace area. Nebuchadnezzar describes it, before his own building operations, as extending from the Euphrates eastward to the Sacred Road; and the old palace-enclosure undoubtedly occupied that site. Traces of the old fortification-wall have been found below the east front of the later palace, and the arched doorway which gave access to its open court, afterwards filled up and built over by Nebuchadnezzar, has been found in a perfect state of preservation.[62]

III. The Throne Room in Nebuchadnezzar's palace at Babylon, showing the recess in the back wall where the throne once stood.

The old palace itself[63] did not reach beyond the western side of Nebuchadnezzar's great court.[64] The upper structure, as we learn from the East India House Inscription,[65] was of crude brick, which was demolished for the later building. But Nabopolassar, following a custom which had survived unchanged from the time of Hammurabi, had placed his crude-brick walls upon burnt-brick foundations. These his son made use of, simply strengthening them before erecting his own walls upon them. Thus this section of the new palace retained the old ground-plan to a great extent unchanged. The strength and size of its walls are remarkable and may in part be explained by the crude-brick upper structure of the earlier building, which necessarily demanded a broader base for its walls.

When Nebuchadnezzar began building he dwelt in the old palace, while he strengthened the walls of its open court on the east and raised its level for the solid platform on which his own palace was to rise.[66] For a time the new and the old palace were connected by two ramps of unburnt-brick,[67] which were afterwards filled in below the later pavement of the great court; and we may picture the king ascending the ramps with his architect on his daily inspection of the work. As soon as the new palace on the east was ready he moved into it, and, having demolished the old one, he built up his own walls upon its foundations, and filled in the intermediate spaces with earth and rubble until he raised its pavement to the eastern level. Still later he built out a further extension[68] along its western side. In the account he has left us of the palace-building the king says: "I laid firm its foundation and raised it mountain-high with bitumen and burnt-brick. Mighty cedars I caused to be stretched out at length for its roofing. Door-leaves of cedar overlaid with copper, thresholds and sockets of bronze I placed in its doorways. Silver and gold and precious stones, all that can be imagined of costliness, splendour, wealth, riches, all that was highly esteemed, I heaped up within it, I stored up immense abundance of royal treasure therein."[69]

A good general idea of the palace ground-plan, in its final form, may be obtained from Fig. 6. The main entrance was in its eastern front, through a gate-way,[70] flanked on its outer side by towers, and known as the Bûb Bêlti, or "Lady Gate," no doubt from its proximity to the temple of the goddess Ninmakh.[71] The gate-house consists of an entrance hall, with rooms opening at the sides for the use of the palace-guard. The eastern part of the palace is built to the north and south of three great open courts,[72] separated from each other by gateways[73] very like that at the main entrance to the palace. It will be noticed that, unlike the arrangement of a European dwelling, the larger rooms are always placed on the south side of the court facing to the north, for in the sub-tropical climate of Babylonia the heat of the summer sun was not courted, and these chambers would have been in the shade throughout almost the whole of the day.

Some of the larger apartments, including possibly the chambers of the inner gateways, must have served as courts of justice, for from the Hammurabi period onward we know that the royal palace was the resort of litigants, whose appeals in the earlier period were settled by the king himself,[74] and later by the judges under his supervision. Every kind of commercial business was carried on within the palace precincts, and not only were regular lawsuits tried, but any transaction that required legal attestation was most conveniently carried through there. Proof of this may be seen in the fact that so many of the Neo-Babylonian contracts that have been recovered on the site of Babylon are dated from the Al-Bît-shar-Bâbili, "the City of the King of Babylon's dwelling," doubtless a general title for the citadel and palace-area. All government business was also transacted here, and we may provisionally assign to the higher ministers and officials of the court the great apartment and the adjoining dwellings on the south side of the Central Court of the palace.[75] For many of the more important officers in the king's service were doubtless housed on the premises; and to those of lower rank we may assign the similar but rather smaller dwellings, which flank the three courts on the north and the Entrance Court upon the south side as well. Even royal manufactories were carried on within the palace, to judge from the large number of alabaster jars, found beside their cylindrical cores, in one room in the south-west corner by the outer palace-wall.[76]

It will be seen from the ground-plan that these dwellings consist of rooms built around open courts or light-wells; most of them are separate dwellings, isolated from their neighbours, and having doors opening on to the greater courts or into passage-ways running up from them. No trace of any windows has been found within the buildings, and it is probable that they were very sparsely employed. But we must not conclude that they were never used, since no wall of the palace has been preserved for more than a few feet in height, and, for the greater part, their foundations only have survived. But there is no doubt that, like the modern houses of the country, all the dwellings, whether in palace or city, had flat roofs, which formed the natural sleeping-place for their inhabitants during the greater part of the year. Towards sunset, when the heat of the day was past, they would ascend to the house-tops to enjoy the evening breeze; during the day a window would have been merely a further inlet for the sun. The general appearance of the palace is no doubt accurately rendered in the sketch already given.[77]