Now Attica was very small, and in the days of her prosperity the population of Athens had increased so much that the state could no longer produce enough food to support the people. The far-seeing policy of Themistocles had made Athens stronger on sea than on land, and by the time of Pericles, the salvation of Athens lay in her navy. She was increasing her sea-power in all directions and establishing herself as mistress all over the Aegean and on the shores of the Euxine. This policy was not only dictated by the greed of power, but by the {291} absolute necessity that if Athens were to live, she should control all the trade routes by which corn reached Greece. Without the corn from the shores of the Euxine, Athens would starve. Sparta was a great land power, and at first this increasing sea-power of Athens did not touch her very closely, but it did affect Corinth, the next sea-power in Greece after Athens. As long as Athens confined her interests to the Aegean and the East, Corinth was not alarmed, but when the Athenians turned to the West and showed their intention of establishing their power there, the Corinthians became seriously alarmed, for this threatened their interests in Sicily and the South of Italy. Corinth had always been hostile to Athens, and she now appealed to Sparta, asking for help to crush Athens. Corinthian envoys went to Sparta, and in a powerful speech one of them set forth the grievances of the Greek world against Athens, representing her power, and entreating the Spartans to lay aside their policy of inaction and to join with them in crushing the Tyrant state.