MESSENIA (Gr. or the S.W. district of the Peloponnese, bounded on the E. by Mt. TaYgetus, on the N. by the river Neda and the Arcadian Mountains, on the S. and W. by the sea. Its area is some 825,000 acres. Historically and economically important is the great plain, watered by the river Pamisus (mod. Pirnatza), the most fertile tract in Greece, producing oranges, citrons, almonds, figs, grapes and olives. The plain is bounded N. by the Nomian Mountains (mod. Tetrasi, 5,210 ft.); W. by the mountains of Cyparissia (4,000 ft.), which attains 3,160 ft. in Mt. Mathia (mod. LykOclimo). Off the south coast of the S.W. peninsula lie the three Oenussae islands and the islet of Theganussa (Venetiko).
At the present day Messenia forms a department with its capital at Kalamata, and a population numbering (according to the census of 1907), 127,991.
The earliest inhabitants of Messenia are said to have been Pelasgians and Leleges (qq.v.). Then came an Aeolo-Minyan immigration. In the Homeric poems eastern Messenia is repre sented as under the rule of Menelaus of Sparta, while the western coast is under the Neleids of Pylos. Dorians under Cresphontes invaded the country from Arcadia and extended their rule over the whole district. The Dorians blending with the previous inhabitants produced a single Messenian race with a strong national feeling. But the fertility of the soil, the warm and genial climate, the mingling of races and the absence of opposition, combined to render the Messenians no match for their hardy and warlike neighbours of Sparta. War broke out which ended in the subjection of Messenia to Sparta (c. 720 B.c.). Two generations later the Messenians revolted, and under the leader ship of Aristomenes (q.v.) kept the Spartans at bay for some
17 years; those Messenians who did not leave the country were reduced to the condition of helots.
Revolt broke out again in 464 B.c.; the insurgents defended themselves for some years on the rock-citadel of Ithome, but eventually they had to leave the Peloponnese and were settled by the Athenians at Naupactus. After the battle of Leuctra (371 B.c.) Epameinondas invited the exiled Messenians to return to their country. The city of Messene (q.v.) was founded in 369 B.C. to be the capital of the country and, like Megalopolis in Arcadia, a check on Sparta. A great part of the land remained very sparsely peopled, and Messenia never again became really powerful. After the fall of the Theban power it became an ally of Philip II. of Macedon. Subsequently it joined the Achaean League, and we find Messenian troops fighting at Sellasia. The Spartan tyrant, Nabis, succeeded in taking the city but was forced to retire by Philopoemen and the Megalopolitans. It again joined the Achaean league, though much weakened by the loss of Abia, Thuria and Pherae, which entered the league as independent members. In 146 B.C. the Messenians were brought under Roman sway by L. Mummius.
In the Middle Ages Messenia shared the fortunes of the rest of the Peloponnese. It was overrun by Slavic hordes, and was one of the battlefields of Byzantines, Franks, Venetians and Turks, who struggled for the possession of the Morea, as recalled by the ruins of the mediaeval strongholds of Kalamata, Coron (anc. Asine, mod. Korone), Modon (Metlione) and Pylos.