=30.= We have anticipated the five or six centuries which followed the Heroic Age, for the sake of giving a connected though brief account of the religious beliefs and customs of the Greeks, without which their history could not be understood. It only remains to mention those oracles through which, from the earliest times to the latest, and even long after the civil existence of Greece was ended, the gods were believed to make known their will to man.
=31.= The oldest of the oracles was that of Zeus at Dodona, where the message of the god was believed to be heard in the rustling of the sacred oaks and beeches, and interpreted by his chosen priests or prophetesses. At Olympia, in Elis, the will of Zeus was read in the appearance of victims sacrificed for the purpose. The oracles of Zeus were comparatively few. The office of revealing the divine will to man devolved usually upon Apollo, who had twenty-two oracles in European and Asiatic Greece.
=32.= Of these the most celebrated was at Delphi, in Phocis, where was a temple of Apollo containing his golden statue and an ever-burning fire of fir-wood. In the center of the temple was a crevice in the ground, whence arose a peculiarly intoxicating vapor. When the oracle was to be consulted, the Pythia, or priestess, took her seat upon the sacred tripod over this opening; and when bewildered or inspired by the vapor, which was supposed to be the breath of the god, she uttered a response in hexameter verses. It was often so obscure,[37] that it required more wit to discern the meaning of the oracle than to determine the best course of conduct without its aid. But so great was the reputation of the Delphic shrine, that not only Greeks, but Lydians, Phrygians, and Romans sent solemn embassies to consult it concerning their most important undertakings.
=33.= What Europe has been to the rest of the world, Greece was to Europe. The same peculiarities of coast and climate which made Europe the best adapted to civilization of all the continents, long made Greece its most highly civilized portion. But as Europe had her northern barbarians, always pressing upon the great mountain barrier of the Pyrenees, Alps, and Carpathians, sometimes bursting their limits and overrunning the more civilized but weaker nations to the southward, so Greece suffered, toward the close of the Heroic Age, from the incursions of the Illyrians on her north-western frontier. The time of this movement was fixed by Greek historians at sixty years after the fall of Troy, or, in our reckoning, B. C. 1124.