AGIS, the name of four Spartan kings : (t ) Son of Eurysthenes, founder of the royal house of the Agiadae (Pausanias iii. 2. I ). His genealogy was traced back to Heracles (Herodotus vii. 204), and he belongs rather to mythology than to history. Tradition ascribed to him the cap ture of Helos, and the institution of the class of serfs called Helots. (q.v.). See Ephorus ap. Strabo, viii. p. 365.
(2) AGIs I., son of Archidamus II., Eurypontid, succeeded his father, probably in 427 B.C., and from his first invasion of Attica in 425 down to the close of the Peloponnesian War was the chief leader of the Spartan operations on land. After the conclusion of the peace of Nicias (421 B.C.) he marched against the Argives in defence of Epidaurus, and after skilful manoeuvring surrounded the Argive army, and seemed to have victory within his grasp when he unaccountably concluded a four months' truce and withdrew his forces. The Spartans were indignant, and when the Argives and their allies broke the truce Agis escaped having his house razed and a fine of 1 oo,000 drachmae imposed only by promising to atone for his error by a signal victory. This promise he fulfilled by routing the forces of the Argive con federacy at the battle of Mantinea (418). In the winter 417-416 a further expedition to Argos resulted in the destruction of the half-finished Long Walls and the capture of Hysiae. In 413, on the suggestion of Alcibiades, he fortified Decelea in Attica, where he remained directing operations until, after the battle of Aegospotami (4o5), he took the leading part in the blockade of Athens, which was ended in the spring of 404 by the surrender of the city. Subsequently he invaded and ravaged Elis. He fell ill on his return from Delphi, where he had gone to dedicate a tithe of the spoils, and died at Sparta, probably in 401.
BIBLIOGRAPHY. —See Thuc. iii. 89, iV. 2. 6, v., vii. 19. 27, viii.; Bibliography. —See Thuc. iii. 89, iV. 2. 6, v., vii. 19. 27, viii.; Xenophon, Hellenica, i. 1, ii. 2. 3, iii. 2. 3 ; Diodorus xii. 35, xiii. 72, 73, 107; Pausanias iii. 8. 3-8; Plutarch, Lysander ix. 14. 22, Alcibiades 23-25, Lycurgus 12, Agesilaus i. 3, de Tranquill. Anim. 6. (See