When Assur-bani-pal died, his empire was fast breaking up. Scythian influence. Under his successor, Assur-etil-ilani, the Scythians penetrated into Assyria and made their way as far as the borders of Egypt. Calah was burned, though the strong walls of Nineveh protected the relics of the Assyrian army which had taken refuge behind them; and when the raiders had passed on to other fields of booty, a new palace was erected among the ruins of the neighbouring city. But its architectural poverty and small size show that the resources of Assyria were at a low ebb. A contract has been found at Sippara, dated in the fourth year of Assur-etil-ilani, though it is possible that his rule in Babylonia was disputed by his Rab-shakeh (vizier), Assur-sum-lisir, whose accession year as king of Assyria occurs on a contract from Nippur (Niffer). The last king of Assyria was probably the brother of Assur-etil-ilani, Sin-sar-iskun (Sin-sarra-uzur), who seems to have been the Sarakos (Saracus) of Berossus. He was still reigning in Babylonia in his seventh year, as a contract dated in that year has been discovered at Erech, and an inscription of his, in which he speaks of restoring the ruined temples and their priests, couples Merodach of Babylon with Assur of Nineveh. Babylonia, however, was again restless.
After the over throw of Samas-sum-yukin, Kandalanu, the Chineladanos of Ptolemy's canon, had been appointed viceroy. Nabopolassar. His successor was Nabopolassar, between whom and the last king of Assyria war broke out. The Scythian king of Ecbatana, the Cyaxares of the Greeks, came to the help of the Babylonians. Nineveh was captured and destroyed by the Scythian army, along with those cities of northern Babylonia which had sided with Babylonia, and the Assyrian empire was at an end.
The seat of empire was now transferred to Babylonia. Nabopolassar Nabonidus. was followed by his son Nebuchadrezzar II., whose reign of 43 years made Babylon once more the mistress of the civilized world. Only a small fragment of his annals has been discovered relating to his invasion of Egypt in 567 B.C., and referring to "Phut of the Ionians." Of the reign of the last Babylonian king, Nabonidus, however, and the conquest of Babylonia by Cyrus, we now have a fair amount of information. This is chiefly derived from a chronological tablet containing the annals of Nabonidus, which is supplemented by an inscription of Nabonidus, in which he recounts his restoration of the temple of the Moon-god at Harran, as well as by a proclamation of Cyrus issued shortly after his formal recognition as king of Babylonia. It was in the sixth year of Nabonidus (549 B.C.) - or perhaps in 553 - that Cyrus, "king of Anshan" in Elam, revolted against his suzerain Astyages, king of "the Manda" or Scythians, at Ecbatana. The army of Astyages betrayed him to his enemy, and Cyrus (q.v.) established himself at Ecbatana, thus putting an end to the empire of the Scythians, which the Greek writers called that of the Medes, through a confusion of Madā or "Medes" with Manda. Invasion by Cyrus. Three years later we find that Cyrus has become king of Persia and is engaged in a campaign in the north of Mesopotamia. Meanwhile Nabonidus has established a camp at Sippara, near the northern frontier of his kingdom, his son - probably the Belshazzar of other inscriptions - being in command of the army.
In 538 B.C. Cyrus invaded Babylonia. A battle was fought at Opis in the month of June, in which the Babylonians were defeated, and immediately afterwards Sippara surrendered to the invader. Nabonidus fled to Babylon, whither he was pursued by Gobryas, the governor of Kurdistan, and on the 16th of Tammuz, two days after the capture of Sippara, "the soldiers of Cyrus entered Babylon without fighting." Nabonidus was dragged out of his hiding-place, and Kurdish guards were placed at the gates of the great temple of Bel, where the services continued without intermission. Cyrus did not arrive till the 3rd of Marchesvan (October), Gobryas having acted for him in his absence. Gobryas was now made governor of the province of Babylon, and a few days afterwards the son of Nabonidus, according to the most probable reading, died. A public mourning followed, which lasted six days, and Cambyses accompanied the corpse to the tomb. Cyrus now claimed to be the legitimate successor of the ancient Babylonian kings and the avenger of Bel-Merodach, who was wrathful at the impiety of Nabonidus in removing the images of the local gods from their ancestral shrines to his capital Babylon. Nabonidus, in fact, had excited a strong feeling against himself by attempting to centralize the religion of Babylonia in the temple of Merodach (Marduk) at Babylon, and while he had thus alienated the local priesthoods the military party despised him on account of his antiquarian tastes.
He seems to have left the defence of his kingdom to others, occupying himself with the more congenial work of excavating the foundation records of the temples and determining the dates of their builders. The invasion of Babylonia by Cyrus was doubtless facilitated by the existence of a disaffected party in the state, as well as by the presence of foreign exiles like the Jews, who had been planted in the midst of the country. One of the first acts of Cyrus accordingly was to allow these exiles to return to their own homes, carrying with them the images of their gods and their sacred vessels. The permission to do so was embodied in a proclamation, in which the conqueror endeavoured to justify his claim to the Babylonian throne. The feeling was still strong that none had a right to rule over western Asia until he had been consecrated to the office by Bel and his priests; and from henceforth, accordingly, Cyrus assumed the imperial title of "king of Babylon." A year before his death, in 529 B.C., he associated his son Cambyses (q.v.) in the government, making him king of Babylon, while he reserved for himself the fuller title of "king of the (other) provinces" of the empire.
It was only when Darius Hystaspis, the representative of the Aryan race and the Zoroastrian religion, had re-conquered the empire of Cyrus, that the old tradition was broken and the claim of Babylon to confer legitimacy on the rulers of western Asia ceased to be acknowledged (see Darius). Darius, in fact, entered Babylon as a conqueror; after the murder of the Magian it had recovered its independence under Nidinta-Bel, who took the name of Nebuchadrezzar III., and reigned from October 521 B.C. to August 520 B.C., when the Persians took it by storm. A few years later, probably 514 B.C., Babylon again revolted under the Armenian Arakha; on this occasion, after its capture by the Persians, the walls were partly destroyed. E-Saggila, the great temple of Bel, however, still continued to be kept in repair and to be a centre of Babylonian patriotism, until at last the foundation of Seleucia diverted the population to the new capital of Babylonia and the ruins of the old city became a quarry for the builders of the new seat of government.
VI. Assyria and Babylonia contrasted. - The sister-states of Babylonia and Assyria differed essentially in character. Babylonia was a land of merchants and agriculturists; Assyria was an organized camp. The Assyrian dynasties were founded by successful generals; in Babylonia it was the priests whom a revolution raised to the throne. The Babylonian king remained a priest to the last, under the control of a powerful hierarchy; the Assyrian king was the autocratic general of an army, at whose side stood in early days a feudal nobility, and from the reign of Tiglath-pileser III. onwards an elaborate bureaucracy. His palace was more sumptuous than the temples of the gods, from which it was quite separate. The people were soldiers and little else; even the sailor belonged to Babylonia. Hence the sudden collapse of Assyria when drained of its fighting population in the age of Assur-bani-pal.