During all this period there was small temptation to transfer the capital to any point within easier striking distance of so powerful a neighbour; and with the principal passes for eastward traffic under foreign control, it was natural that the Euphrates route to Northern Mesopotamia and the Mediterranean coast should continue to be the chief outlet for Babylonian commerce. But on the incorporation of the country within the Persian empire all danger of interference with her eastern trade was removed; and it is a testimony to the part Babylon had already played in history that she continued to be the capital city of Asia for more than two centuries. Cyrus, like Alexander, entered the city as a conqueror, but each was welcomed by the people and their priests as the restorer of ancient rights and privileges. Policy would thus have been against any attempt to introduce radical innovations. The prestige the city enjoyed and the grandeur of its temples and palaces doubtless also weighed with the Achæmenian kings in their choice of Babylon for their official residence, except during the summer months. Then they withdrew to the cooler climate of Persepolis or Ecbatana, and during the early spring, too, they might transfer the court to Susa; but they continued to recognize Babylon as their true capital. In fact, the city only lost its importance when the centre of government was removed to Seleucia in its own immediate neighbourhood. Then, at first possibly under compulsion, and afterwards of their own freewill, the commercial classes followed their rulers to the west bank of the Tigris; and Babylon suffered in proportion. In the swift rise of Seleucia in response to official orders, we may see clear proof that the older city's influence had been founded upon natural conditions, which were shared in an equal, and now in even a greater degree, by the site of the new capital.
FIG. 1.
DIAGRAM TO ILLUSTRATE THE POLITICAL CENTRE OF GRAVITY IN BABYLONIA.
The circle marks the limits within which the capital shifted from the period of the First Dynasty onwards. It was only under the abnormal conditions produced by the Moslem conquest that Kûfa and Basra became for five generations the twin capitals of 'Irâk; this interval presents a parallel to the earlier period before the rise of Babylon.
The secret of Babylon's greatness is further illustrated by still later events in the valley of the Euphrates and the Tigris. The rise of Ctesiphon on the left bank of the river was a further result of the eastward trend of commerce. But it lay immediately opposite Seleucia, and marked no fresh shifting of the centre of gravity. Of little importance under the Seleucid rulers, it became the chief city of the Arsacidæ, and, after the Parthian Empire had been conquered by Ardashir I., it continued to be the principal city of the province and became the winter residence of the Sassanian kings. When in 636 A.D. the Moslem invaders defeated the Persians near the ruins of Babylon and in the following year captured Ctesiphon, they found that city and Seleucia to which they gave the joint name of Al-Madâin, or "the cities," still retaining the importance their site had acquired in the third century b.c. Then follows a period of a hundred and twenty-five years which is peculiarly instructive for comparison with the earlier epochs of Babylonian history.
The last of the great Semitic migrations from Arabia had resulted in the conquests of Islam, when, after the death of Mohammed, the Arab armies poured into Western Asia in their efforts to convert the world to their faith. The course of the movement, and its effect upon established civilizations which were overthrown, may be traced in the full light of history; and we find in the valley of the Tigris and Euphrates a resultant economic condition which forms a close parallel to that of the age before the rise of Babylon. The military occupation of Mesopotamia by the Arabs closed for a time the great avenues of transcontinental commerce; and, as a result, the political control of the country ceased to be exercised from the capital of the Sassanian kings and was distributed over more than one area. New towns sprang into being around the permanent camps of the Arab armies. Following on the conquest of Mesopotamia, the city of Basra was built on the Shatt el-'Arab in the extreme south of the country, while in the same year, 638 A.D., Kûfa was founded more to the north-west on the desert side of the Euphrates. A third great town, Wâsit, was added sixty-five years later, and this arose in the centre of the country on both banks of the Tigris, whose waters were then passing along the present bed of the Shatt el-Hai. It is true that Madâin retained a measure of local importance, but during the Omayyad Caliphate Kûfa and Basra were the twin capitals of 'Irâk.[13]
Thus the slackening of international connections led at once to a distribution of authority between a north and a south Babylonian site. It is true that both capitals were under the same political control, but from the economic standpoint we are forcibly reminded of the era of city-states in Sumer and Akkad. Then, too, there was no external factor to retain the centre of gravity in the north; and Erech more than once secured the hegemony, while the most stable of the shifting dynasties was the latest of the southern city of Ur. The rise of Babylon as the sole and permanent capital of Sumer and Akkad may be traced, as we shall note, to increased relations with Northern Syria, which followed the establishment of her dynasty of West-Semitic kings.[14] And again we may see history repeating herself, when Moslem authority is removed to Baghdad at the close of the first phase in the Arab occupation of Mesopotamia. For on the fall of the Omayyad dynasty and the transference of the Abbasid capital from Damascus to the east, commercial intercourse with Syria and the west was restored to its old footing. Basra and Kûfa at once failed to respond to the changed conditions, and a new administrative centre was required. It is significant that Baghdad should have been built a few miles above Ctesiphon, within the small circle of the older capitals;[15] and that, with the exception of a single short period,[16] she should have remained the capital city of 'Irâk. Thus the history of Mesopotamia under the Caliphate is instructive for the study of the closely parallel conditions which enabled Babylon at a far earlier period to secure the hegemony in Babylonia and afterwards to retain it.
From this brief survey of events it will have been noted that Babylon's supremacy falls in the middle period of her country's history, during which she distributed a civilization in the origin of which she played no part. When she passed, the culture she had handed on passed with her, though on Mesopotamian soil its decay was gradual. But she had already delivered her message, and it has left its mark on the remains of other races of antiquity which have come down to us. We shall see that it was in three main periods that her influence made itself felt in any marked degree beyond the limits of the home-land. The earliest of these periods of external contact was that of her First Dynasty of West-Semitic rulers, though the most striking evidence of its effect is only forthcoming after some centuries had passed. In the second period the process was indirect, her culture being carried north and west by the expansion of Assyria. The last of the three epochs coincides with the rule of the Neo-Babylonian kings, when, thanks to her natural resources, the country not only regained her independence, but for a short time established an empire which far eclipsed her earlier effort. And in spite of her speedy return, under Persian rule, to the position of a subject province, her foreign influence may be regarded as operative, it is true in diminishing intensity, well into the Hellenic period.