Under Tiglath-pileser III. arose the Tiglath-pileser III. second Assyrian empire, which differed from the first in its greater consolidation. For the first time in history the idea of centralization was introduced into politics; the conquered provinces were organized under an elaborate bureaucracy at the head of which was the king, each district paying a fixed tribute and providing a military contingent. The Assyrian forces became a standing army, which, by successive improvements and careful discipline, was moulded into an irresistible fighting machine, and Assyrian policy was directed towards the definite object of reducing the whole civilized world into a single empire and thereby throwing its trade and wealth into Assyrian hands. With this object, after terrorizing Armenia and the Medes and breaking the power of the Hittites, Tiglath-pileser III. secured the high-roads of commerce to the Mediterranean together with the Phoenician seaports and then made himself master of Babylonia. In 729 B.C. the summit of his ambition was attained, and he was invested with the sovereignty of Asia in the holy city of Babylon. Two years later, in Tebet 727 B.C., he died, but his successor Ululā, who took the name of Shalmaneser IV., continued the policy he had begun.
Shalmaneser died suddenly in Tebet 722 B.C., while pressing the siege of Samaria, and the seizure of the throne by another general, Sargon, on the 12th of the month, gave the Babylonians an opportunity to revolt. Merodach-baladan. In Nisan the Kaldā prince, Merodach (Marduk)-baladan, entered Babylon and was there crowned legitimate king. For twelve years he successfully resisted the Assyrians; but the failure of his allies in the west to act in concert with him, and the overthrow of the Elamites, eventually compelled him to fly to his ancestral domains in the marshes of southern Babylonia. Sargon, who meanwhile had crushed the confederacy of the northern nations, had taken (717 B.C.) the Hittite stronghold of Carchemish and had annexed the future kingdom of Ecbatana, was now accepted as king by the Babylonian priests and his claim to be the successor of Sargon of Akkad acknowledged up to the time of his murder in 705 B.C. Sennacherib. His son Sennacherib, who succeeded him on the 12th of Ab, did not possess the military or administrative abilities of his father, and the success of his reign was not commensurate with the vanity of the ruler.
He was never crowned at Babylon, which was in a perpetual state of revolt until, in 691 B.C., he shocked the religious and political conscience of Asia by razing the holy city of Babylon to the ground. His campaign against Hezekiah of Judah was as much a failure as his policy in Babylonia, and in his murder by his sons on the 20th of Tebet 681 B.C. both Babylonians and Jews saw the judgment of heaven.
Esar-haddon, who succeeded him, was of different calibre from Esar-haddon. his father. He was commanding the army in a campaign against Ararat at the time of the murder; forty-two days later the murderers fled from Nineveh and took refuge at the court of Ararat. But the Armenian army was utterly defeated near Malatia on the 12th of Iyyar, and at the end of the day Esar-haddon was saluted by his soldiers as king. He thereupon returned to Nineveh and on the 8th of Sivan formally ascended the throne.
One of his first acts was to restore Babylon, to send back the image of Bel-Merodach (Bel-Marduk) to its old home, and to re-people the city with such of the priests and the former population as had survived massacre. Then he was solemnly declared king in the temple of Bel-Merodach, which had again risen from its ruins, and Babylon became the second capital of the empire. Esar-haddon's policy was successful and Babylonia remained contentedly quiet throughout his reign. In February (674 B.C.) the Assyrians entered upon their invasion of Egypt (see also Egypt: History), and in Nisan (or March) 670 B.C. an expedition on an unusually large scale set out from Nineveh. The Egyptian frontier was crossed on the 3rd of Tammuz (June), and Tirhaka, at the head of the Egyptian forces, was driven to Memphis after fifteen days of continuous fighting, during which the Egyptians were thrice defeated with heavy loss and Tirhaka himself was wounded. On the 22nd of the month Memphis was entered by the victorious army and Tirhaka fled to the south.
A stele, commemorating the victory and representing Tirhaka with the features of a negro, was set up at Sinjirli (north of the Gulf of Antioch) and is now in the Berlin Museum. Two years later (668 B.C.) Egypt revolted, and while on the march to reduce it, Esar-haddon fell ill and died (on the 10th of Marchesvan or October). Assur-bani-pal. Assur-bani-pal succeeded him as king of Assyria and its empire, while his brother, Samas-sum-yukin, was made viceroy of Babylonia. The arrangement was evidently intended to flatter the Babylonians by giving them once more the semblance of independence. But it failed to work. Samas-sum-yukin became more Babylonian than his subjects; the viceroy claimed to be the successor of the monarchs whose empire had once stretched to the Mediterranean; even the Sumerian language was revived as the official tongue, and a revolt broke out which shook the Assyrian empire to its foundations. After several years of struggle, during which Egypt recovered its independence, Babylon was starved into surrender, and the rebel viceroy and his supporters were put to death.
Egypt had already recovered its independence (660 B.C.) with the help of mercenaries sent by Gyges of Lydia, who had vainly solicited aid from Assyria against his Cimmerian enemies. Next followed the contest with Elam, in spite of the efforts of Assur-bani-pal to ward it off. Assyria, however, was aided by civil war in Elam itself; the country was wasted with fire and sword, and its capital Susa or Shushan levelled with the ground. But the long struggle left Assyria maimed and exhausted. It had been drained of both wealth and fighting population; the devastated provinces of Elam and Babylonia could yield nothing with which to supply the needs of the imperial exchequer, and it was difficult to find sufficient troops even to garrison the conquered populations. Assyria, therefore, was ill prepared to face the hordes of Scythians - or Manda, as they were called by the Babylonians - who now began to harass the frontiers. A Scythian power had grown up in the old kingdom of Ellip, to the east of Assyria, where Ecbatana was built by a "Manda" prince; Asia Minor was infested by the Scythian tribe of Cimmerians, and the death of the Scythian leader Dugdammē (the Lygdamis of Strabo i. 3. 16) was regarded by Assur-bani-pal as a special mark of divine favour.