The government was still despotic, somewhat relieved by the more humane and independent habits and traditions of a hardier race. A number of changes of dynasty by violence occurred, but they were merely revolutions of the palace. The vast wealth and power inherited from the subject empires gradually corrupted the conquerors. Their armies became vast crowds of comparatively undisciplined troops, who were accustomed to bear everything before them by their irresistible weight. Their conquests on the northern and eastern coasts of Asia Minor brought them in conflict with the Greeks, who had many colonies long settled in that region, and the Persians soon undertook to subdue that intelligent and independent people. Their signal failure had the effect to greatly stimulate the development of the Greek national spirit, and to awaken its intellectual enthusiasm, and the mighty armies of the Persians were destined to be annihilated by the small but resolute forces of the little republics. 16. Thirteen sovereigns ruled during the continuance of the Persian empire. Except the conquest of Egypt, they did not very greatly extend the boundaries formed by Cyrus; but the national features of the subject peoples were gradually effaced, and the whole brought to the common level of civilization. When Alexander, the great Grecian soldier, appeared with his army of 35,000 men he scattered the hosts of the Persian king, Darius, as the wind drives the leaves of the forest; and the vast empire, so long accustomed to bow to the fate of battles, became the unresisting heritage of the conquerer. These five great monarchies were continuous—in part on the same soil—the centre having always been the fertile valleys of the Euphrates and the Tigris; the successor stepping into the place and carrying out the general plans of his immediate predecessor, but on a broader scale and in an increasingly enlightened manner. Through all these long centuries a mysterious, and, apparently, still more ancient race had occupied Egypt, only occasionally interfering with, or being disturbed by, the surging sea of strife that raged and foamed so near them, which at length forced them from their seclusion and bore them on in the general tide of improvement. 17. The Egyptian monarchy presents many very curious and difficult problems. Possessing the most perfect organization in the earliest times of which we have any knowledge, the traces of its beginnings quite fail us, although, more than any other nation, it loved to build great and impressive monuments and record on them, in the most minute manner, the singular habits and monotonous daily life of its people. The first of those monuments, which, by many signs, must date very nearly as far back in the remote past as the earliest dawn of organization among any other people of whom we can gather any certain traces, indicate a long settled state, a high degree of organization, considerable culture and great resources.