Archidamus, the name of five kings of Sparta, of the Proclid or Eurypontid line. The first of the name, son of Anaxidamus, lived during the war with Tegea, about 668 B. C. The second, son of Zeuxidamus, reigned 469-427 B. C. In 464 occurred the terrible earthquake which almost destroyed Sparta, when Archidamus by his energy probably saved the surviving citizens from massacre by the helots, He commanded in the wars against the revolted Messenians. In the discussions at Sparta and Corinth prior to the rupture with Athens he was prominent as an advocate of peace and moderation. In the Peloponnesian war he commanded three expeditions against Attica and one against Plataea. His grandson Archidamus III., son of Agesi-laus II., reigned 361-338 B. C. In 367 he had defeated the Arcadians and Argives in the "tearless battle," so called by the Spartans because they did not lose a man; and in 362 he had successfully defended Sparta against Epami-nondas. In the sacred war he aided the Pho-cians against the Macedonians with money and men, but toward its close he retired on the approach of Philip, leaving the Phocians to their fate.

He was killed in Italy, in a battle fought in aid of the Tarentines, on the day of the battle of Cha2ronea. Archidamus IV., his grandson, and son of Eudamidas I., is only known from his defeat by Demetrius Polior-cetes in 296 B. C. Archidamus V., last of the Proclid line, son of Eudamidas II., possessed himself of the throne in 240 B. C, but was soon slain by the murderers of his brother and predecessor Agis IV.