You remember, do you not, how the sons of Pelops had driven the Heraclidae, or sons of Hercules, out of the peninsula which was called the Peloponnesus? This same peninsula is now called Morea, or the mulberry leaf, because it is shaped something like such a leaf, as you will see by looking at your map.
The Heraclidae had not gone away willingly, but were staying in Thessaly, in the northern part of Greece, where they promised to remain one hundred years without making any attempt to come back.
Shortly after the end of the Trojan War, this truce of a hundred years came to an end; and the Heraclidae called upon their neighbors the Dorians to join them, and help them win back their former lands.
Led by three brave chiefs, the allies passed through Greece proper, along the Isthmus of Corinth, and, spreading all over the Peloponnesus, soon took possession of the principal towns. The leading members of the family of Hercules took the title of kings, and ruled over the cities of Argos, Mycenae, and Sparta.
The Dorians, who had helped the Heraclidae win back their former possessions, now saw that the land here was better than their home in the mountains, so they drove all the rest of the Ionians out of the country, and settled there also.
Thus driven away by the Dorians and the Heraclidae, these Ionians went to Athens, to the neighboring islands, and even to the coast of Asia Minor, south of the ruined city of Troy, where they settled in great numbers. They called the strip of land which they occupied Ionia, and founded many towns, some of which, such as Ephesus and Miletus, were destined to become famous.
Of course, the Ionians were very angry at thus being driven away from home; and those who had gone to live in Athens soon asked Codrus, the Athenian king, to make war against the Heraclidae of Sparta.