Elis or Ilia

(Greek: Ηλεία, Ileia) is one of the regional units of Greece. It is part of the region of Western Greece. It is situated in the western part of the Peloponnese peninsula. Its capital is Pyrgos.

In classical antiquity, Elis was an independent state, centred on the town Elis and included the sanctuary at Olympia, where the Ancient Olympic Games were held between 776 BC and 394 AD. After 146 BC, Elis was part of the province Achaea within the Roman Empire. In the Migration Period (3rd - 4th century AD) Vandals and Visigoths rampaged through the region. After the final partition of the Roman Empire in 395 Elis was ruled by the Byzantine Empire.

In the aftermath of the Fourth Crusade, crusaders from Western Europe (traditionally referred to as Franks in southeastern Europe) established the principality of Achaea in territory of the defeated Byzantine Empire, including Elis. They built castles like Chlemoutsi. The principality lasted from 1204 until 1460, when it was conquered by the Ottoman Empire.

The Ottoman Empire ruled most of Greece until the Greek War of Independence of 1821. The Venetian Republic controlled a few coastal towns in the 1490s, early 16th century and from 1686 until 1715. Battlegrounds of the Greek War of Independence in Elis include Chlemoutsi, Gastouni, Lala, Lampeia, Pyrgos and Andritsaina.

As a part of independent Greece, Elis experienced an economic and agricultural upswing in the first decennia after the war of independence. Houses were built, and Pyrgos became a regional centre. Like most of the Peloponnese, the area was unaffected during World War I. As a result of the Greco-Turkish War (1919–1922), Greek refugees from Asia Minor settled into a.o. the area around Amaliada.

World War II struck parts of Elis, houses were damaged, leaving people homeless, and afterwards the Greek Civil War caused more destruction and economic decline. The return to democracy after the Greek military junta of 1967–1974, and Greece joining the European Communities in 1981 stimulated economic development and improvement of infrastructure.