Agis II (d. c.
401 BC) was a
Eurypontid king of
Sparta, the eldest son of
Archidamus II and half brother of
Agesilaus. He ruled with his
Agiad co-monarch
Pausanius.
He succeeded his father, probably in
427 BC, and as king was the chief leader of Spartan military
operations on land. When the
Peloponnesian War broke out, Agis led the invasion of
Attica in
425 BC.
After the conclusion of the
peace of Nicias (
421 BC) 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, in flagrant disregard of the truce, took
Arcadian Orchomenus and prepared to march on
Tegea, their fury knew no bounds, and Agis escaped having his house razed and a fine of 100,000
drachmae imposed only by promising to atone for his error by a signal victory. This promise he brilliantly fulfilled by routing the forces of the Argive confederacy at
Mantinea (
418), the moral effect of which was out of all proportion to the losses inflicted on the enemy. 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 (
405), he took the leading part in the blockade of Athens, which was ended in spring 404 by the surrender of the city.
Subsequently he invaded and ravaged
Elis, forcing the Eleans to acknowledge the freedom of their
Perioeci (citizens of cities conquered by Sparta, who were given some privileges) and to allow Spartans to take part in the
Olympic Games and sacrifices. He fell ill on his return from
Delphi, where he had gone to dedicate a tithe of the spoils, and, probably in
401, died at
Sparta, where he was buried with unparalleled solemnity and pomp.
He was succeeded by
Agesilaus. 
