By frequent plundering raids into their territory, the Assyrians incurred the lasting hatred of the Medes, who, urged on by a spirit of revenge, united in 606 B.C. under a Median prince to aid the king of Babylonia against the Assyrian monarch. Having defeated the army, the Medes pursued, and shut the Assyrian force within the walls of Nineveh. Thereupon they made an assault upon the defenses of the city and carried the day. The capital of Assyria and all the wealthy cities of the realm were overrun, plundered and burned, while the surviving inhabitants were so widely scattered that we hear no more about them. Before this the Medes had cared little for luxury and ease, although they always delighted in a certain barbaric splendor. With the vast treasure of Nineveh their king now built a palace of extensive proportions. Its halls and pillars were of woods, its courts wide and the whole structure magnificent. No wood was left visible, all being concealed by a coating of silver tiles. Herodotus wrote thus of the palace walls: "The walls enclose the palace, rising in circles, one within the other. The plan of the place is that each of the walls should out-top the one beyond it by the battlements. The nature of the ground, which is a gentle slope, favors this arrangement in some degree, but it was mainly effected by art. The number of the circles is seven, the royal palace and the treasuries standing within the last. Of the outer wall, the battlements are white; of the next, black; of the third, scarlet; of the fourth, blue; of the fifth, orange; all these are covered with paint. The last two have their battlements coated respectively with silver and gold." We may gain some idea of the wealth represented by this building when we learn that the king of Persia carried away the greater portion of the gold and silver decorations for his palace; Alexander the Great removed the silver tiling from the roof, and some seventy years later another conqueror found about $5,000,000 worth of gold and silver plating overlooked by his predecessors. While no former palace may have exceeded this in actual outlay of wealth, others may have been more artistic, for the Medes reached no special architectural skill.