Elis, or Eleia (Greek, Modern: Ήλιδα Ilida, Ancient: Ἦλις Ēlis; Doric: Ἆλις Alis; Elean: Ϝαλις Walis, ethnonym: Ϝαλειοι) is an ancient district that corresponds with the modern Elis regional unit. It is in southern Greece on the Peloponnesos peninsula, bounded on the north by Achaea, east by Arcadia, south by Messenia, and west by the Ionian Sea. Over the course of the archaic and classical periods, the polis of Elis controlled much of the region of Elis, most probably through unequal treaties with other cities, which will have had perioikic status.
The first Olympic festival was organized in Elean land, Olympia, Greece by the authorities of Elis in the 8th century BCE, with tradition dating the first games at 776 BCE. The Hellanodikai, the judges of the Games, were of Elean origin.
The local form of the name was Valis, or Valeia, and its meaning, in all probability, “the lowland” (compare with the word "valley"). In its physical constitution Elis is similar to Achaea and Arcadia; its mountains are mere offshoots of the Arcadian highlands, and its principal rivers are fed by Arcadian springs.
According to Strabo, the first settlement was created by Oxylus the Aetolian who invaded there and subjugated the residents. The city of Elis underwent synoikism—as Strabo notes—in 471 BC. Elis held authority over the site of Olympia and the Olympic games.
The spirit of the games had influenced the formation of the market: apart from the bouleuterion, which was housed in one of the gymnasia, most of the other buildings were related to the games, including two gymnasia, a palaestrum, and the House of the Hellanodikai.