In the days of her prosperity Athens began to make herself not only a strong, but also a beautiful, city. The temples and other structures which were raised on the Acropolis during the Age of Pericles still excite, even in their ruins, the envy and wonder of mankind. [17] Athens at this time was also the center of Greek intellectual life. In no other period of similar length have so many admirable books been produced. No other epoch has given birth to so many men of varied and delightful genius. The greatest poets, historians, and philosophers of Greece were Athenians, either by birth or training. As Pericles himself said in a noble speech, Athens was "the school of Hellas." [18] 36. THE PELOPONNESIAN WAR, 431-404 B.C. INEVITABLENESS OF THE WAR The brilliant Age of Pericles had not come to an end before the two chief powers in the Hellenic world became involved in a deadly war. It would seem that Athens and Sparta, the one supreme upon the sea, the other at the head of the Peloponnesus, might have avoided a struggle which was sure to be long and costly. But Greek cities were always ready to fight one another. When Athens and Sparta found themselves rivals for the leadership of Greece, it was easy for the smouldering fires of distrust and jealousy to flame forth into open conflict. "And at that time," says Thucydides, the Athenian historian who described the struggle, "the youth of Sparta and the youth of Athens were numerous; they had never seen war, and were therefore very willing to take up arms." [19] [Illustration: Map, GREECE at Opening of the PELOPONNESIAN WAR 431 B.C.] [Illustration: THE "MOURNING ATHENA" (Acropolis Museum, Athens) A tablet of Pentelic marble. Athena, leaning on her spear, is gazing with downcast head at a grave monument.] ORIGIN OF THE WAR The conflict was brought on by Corinth, one of the leading members of the Peloponnesian League and, next to Athens, the most important commercial power in Greece. She had already seen her once-profitable trade in the Aegean monopolized by Athens. That energetic city was now reaching out for Corinthian commerce in Italian and Sicilian waters. When the Athenians went so far as to interfere in a quarrel between Corinth and her colony of Corcyra, even allying themselves with the latter city, the Corinthians felt justly resentful and appealed to Sparta for aid. The Spartans listened to their appeal and, with the apparent approval of the Delphic oracle which assured them "that they would conquer if they fought with all their might," [20] declared war. RESOURCES OF THE CONTESTANTS