Ancient district, eastern central Greece. It was bordered by the Aegean Sea on the south and east and included the island of Salamis; its chief cities were Athens, Piraeus, and Eleusis. Its coastal settlements were enriched by maritime trade. Originally inhabited by Pelasgians, it was a center of Mycenaean culture in the 2nd millennium BC; the Ionian Greeks invaded it c. 1300 BC. The territory was unified under Athens by 700 BC, traditionally through the efforts of King Theseus.