North-west of the palace of Nabopolassar, and deep below the three fortification walls which here lie in front of the Southern Citadel, there are the remains of four ancient walls, the discovery of which has been of great importance for the topography of Babylon. All four are the rounded-off corners—if we may call them so—of quay walls which slope sharply on their north and west fronts. All four are built with a lavish number of stamped and inscribed bricks, so that no doubt whatever can exist as to their use and name.

Each of these quay walls represents a rebuilding of the one behind it, and indicates a thrusting forward of the quay front to the north and west. They consist of good burnt brick, and are for the most part laid in pure asphalt (section on Fig. 87).

The wall of Sargon is the thickest, but with its crown it only attains a height of .27 metres below zero, where it is covered over with a thick layer of asphalt. Above this burnt brick has never been laid, crude brick may have been, but there is nothing to show it. Where the wall abuts on the line of the Southern Citadel it is cut away to make room for the new building. The corner is formed of a circular projecting bastion. In one special course of the front of the bastion, as well as of the straight extent of the wall, in one continuous row, there are inscribed bricks (Fig. 86) with the following legend: “To Marduk! the great Lord, the divine creator who inhabits Esagila, the Lord of Babil, his lord; Sargon the mighty king, King of the land of Assur, King of all, Governor of Babil, King of Sumer and Akkad, the nourisher of Esagila and Ezida. To build Imgur-Bel was his desire: he caused burnt brick of pure kirû to be struck, built a kâr with tar and asphalt on the side of the Ishtar Gate to the bank of the Euphrates in the depth of the water (?), and founded Imgur-Bel and Nimitti-Bel mountain high, firm upon it. This work may Marduk, the great lord, graciously behold and grant Sargon, the prince who cherishes him, life! Like the foundation stone of the sacred city may the years of his reign endure” (trans. by Delitzsch).

The two great fortifications of Imgur-Bel and Nimitti-Bel, so far as Sargon marks them out as his work, are no longer to be recognised. They must have been destroyed by the buildings of Nabopolassar and Nebuchadnezzar on the Southern Citadel. These cannot, however, have stood exactly over our wall, which is only 8 metres broad. Two ordinary fortification walls, such as the two mud walls which stand here above the walls of Sargon, with their intermediate space of one metre filled in with rubbish, occupy with the outer spring of their towers a breadth of 23 metres. Thus they must have lain behind, and Sargon’s wall must have served practically to protect the bank, exactly as we have already observed in the moat wall of Imgur-Bel.

It is an important point that Sargon mentions the position of his wall: on the side of the Ishtar Gate to the bank of the Euphrates. This shows that in Sargon’s time the Euphrates flowed here.

The Nabopolassar inscriptions on the bricks of his wall that directly adjoins the Sargon wall are, some of them stamped, some chiselled, and some written. They are, however, placed without any sort of method, mixed together in close proximity in all three periods of the wall. In the stamped legend (Fig. 88) the king states that he had bright burnt bricks struck, and with them made the wall of the Arachtu. Thus in the time of Nabopolassar the Arachtu must have flowed here, and indeed at exactly the same place where, according to the Sargon bricks, the Euphrates flowed. The difficulties raised by this circumstance, as well as by a number of statements in the Babylonian literature, may be overcome in two different ways. Either Arachtu is only another term for Euphrates, or we must arrive at the somewhat involved conclusion that in course of time the Euphrates frequently changed its bed and had interchanged with that of the Arachtu. In this case the ancient Euphrates must be supposed to have described a curve or bow towards the west, the chord of which was the Arachtu in its straight southward course, thus forming an island of half-moon shape. This would have been the position of affairs which Sennacherib happened upon when he cast the zikurrat Etemenanki into the Arachtu.

In Sargon’s time, on the contrary, the western bed of the Euphrates would have been sanded up, and its waters would have flowed directly in the bed of the earlier Arachtu, and thus past our Sargon wall. Nabopolassar, on the other hand, would have restored the Arachtu, for by his time the Euphrates must have once more resumed its earlier western channel, while Nebuchadnezzar would have destroyed the Arachtu, and extended his citadel actually to the Euphrates. As already said, this is a very perplexing theory, but it is the only one that remains for those who reject the complete identity of the Euphrates and the Arachtu.

The building of the Southern Citadel destroyed the Arachtu wall at this point, but immediately to the south of the Southern Citadel the excavations have once more laid it bare and followed it up nearly to the Amran mound. Here also there are numerous Arachtu bricks of Nabopolassar in the brick masonry.

On the inscribed bricks (Fig. 89) it is stated that “Nabopolassar, etc., the restorer of Esagila and Babylon, made the wall of the Arachtu for Marduk, his lord.” In this the explicit placing together of Babylon and Esagila as two parallel names of equal importance is very striking. It entirely agrees, however, with what has been already said of the original and actual Babylon, in its narrowest meaning, that in the earliest period Esagila was independent of it (cf. p. 87 et seq.).

The inscriptions chiselled on the burnt brick (Fig. 90) state that “Nabopolassar, etc., surrounded the Dûr of Babylon with a wall of burnt brick for protection.” Of this we have found only four examples, and they are all in the walls to the north of the Southern Citadel.

The beginning of the oldest Nabopolassar wall rests on the round tower of the Sargon wall. Its bricks, which are laid in pure asphalt, are very irregular in size. Their length varies between 30, 31, 32, 33, and 34 centimetres; the last have the chiselled inscriptions. The wall outside has a decided batter and inside is markedly stepped. It reaches only to 20 centimetres below zero, and on it was placed, at the part that runs from north to south, a wall of brick rubble.

At the rounded-off corner a wall, of which a small portion only now remains, stretches out to the west, and belongs to a second building period (Fig. 91).

Immediately in front lies the building of the third period, which towards the east only extends a very short way beyond the corner, but of which the north to south portion adds to the earliest building a strip of land about 16 metres broad. It rises higher, and is as much as one metre above zero; in the west it is formed of broken brick, in the north of crude brick. This wall passes under the two mud walls, and within the Southern Citadel it breaks off with a set-back. This latter must certainly have formed part of an outlet of which the corresponding half must have been destroyed by the building of the Southern Citadel. In this place a bonding of the wall front is employed, which rarely occurs elsewhere. It is formed throughout of one whole brick with a half one behind it, followed by a half brick with a whole one behind it. In the course above there is the same arrangement shifted by a half brick placed sideways. This same method of bonding occurs with Nebuchadnezzar’s bricks at the stairway which leads up to the north-east corner of the Kasr.

It is now evident that the older moat wall is also no other than an Arachtu wall, which for the greater part of its northern length lay in front of its predecessor, with no intervening space, while its western portion added once more a strip of land to the old enclosure.