From the numerous large mound-ruins visible on the Mesopotamian plains, it is evident that the work of excavation is only commenced. The long-sealed book of Assyrian history and antiquities has only begun to be unrolled; and in the course of another generation the labours of Layard will probably be as far exceeded as those of Belzoni in Egypt have been by the recent investigations of Lepsius and Champollion-le-Jeune. It is needless, then, at present to waste time in the discussion of moot points in Assyrian history, which in a few years fresh discoveries may at once set definitively at rest. As yet, Assyrian chronology has been but little advanced by the recent researches,—and this principally owing to the circumstance, already mentioned, that the sculptures and inscriptions of each palace relate only to the career of the particular king who erected or embellished it. All we know is, that the palaces at Nimroud (if we except the unfinished one) must have been built at least nine centuries B.C.; but that the earliest of them may have been reared by the great Ninus himself[147] (2000 B.C.),—a most unsatisfactory state of knowledge; and that the palaces at the other angles of the city—namely, Kouyunjik, Karamles, and Khorsabad—were erected, to all appearance, between the ninth and sixth centuries B.C. We know, however, with all certainty, that a great crisis and convulsion in the fortunes of the State occurred between the erection of the earlier and later series of palaces. This convulsion was probably occasioned by the successful revolt of the Medes under Arbaces, and the capture of Nineveh, about 950 B.C., which brought to an end the ancient dynasty of Ninus and Semiramis, after thirteen centuries of power, and established a new family on the throne. Ninus—whose character as a great hunter of the lion and panther tallies with the scriptural accounts of Nimrod—is said, by the general consent of many ancient writers, to have founded the Assyrian monarchy more than two thousand years before Christ,—doing so in the midst of a people far advanced in civilisation, whose works, says Moses of Chorene, the new-comers endeavoured to destroy, and whose knowledge of the arts was taken advantage of by the conquerors in the erection and embellishment of their palaces. In corroboration of this it may be stated, that of all the specimens of Assyrian art which have been discovered, the most ancient are invariably the best,—a curious fact, agreeing with, but not establishing, the hypothesis that the builders of the most ancient edifices at Nineveh were assisted by a people of skill superior to their own.