Thucydides on the Battle of Mantinea (418 BCE)
Battle of Mantinea (418 BCE): important battle, in which Sparta restored its reputation as superpower, by defeating a coalition of Argos, Mantinea, and Elis, supported by Athens.

In the spring of 421, the Athenians and Spartans concluded the Peace of Nicias. After eight years of fighting and an uneasy truce of two years, the Archidamian War was over. Sparta, which had gone to war "to liberate Greece" had not succeeded in dissolving Athens' Delian League had had, in one word, lost. Even worse, its reputation of invincibility was destroyed when 292 Spartans surrendered at Sphacteria, and it appeared to have abandoned its allies Thebes, Megara, and Corinth, which were deeply disappointed: whereas they had suffered most, Sparta gave up first.
In the next years, Athens concluded a new alliance with the democratic states on the Peloponnese: Argos, Mantinea, and Elis. In 418, the Spartans attacked the allies, and forced Athens to choose between either its Spartan alliance (which meant abandoning its allies), or its treaty with Argos, Mantinea, and Elis (and risking an open war with Sparta in its backyard). As it turned out, Athens preferred the second option, and when the Spartan king Agis II marched to the north, the Athenians supported the democrats. In 418, a battle was fought at Mantinea, and the Spartan king Agis defeated his enemies. Now, Athens and the democratic were discredited.
Thucydides describes the fight. His account is a classical description of a hoplite battle. The translation of History of the Peloponnesian War 5.66-74 was made by Richard Crawley.
[5.73.1] The army of the Argives and their allies, having given way in this quarter, was now completely cut in two, and the Spartan and Tegean right simultaneously closing round the Athenians with the troops that outflanked them, these last found themselves placed between two fires, being surrounded on one side and already defeated on the other. Indeed they would have suffered more severely than any other part of the army, but for the services of the cavalry which they had with them. |
[5.73.2] Agis also on perceiving the distress of his left opposed to the Mantineans and the thousand Argives, ordered all the army to advance to the support of the defeated wing; and while this took place, as the enemy moved past and slanted away from them, the Athenians escaped at their leisure, and with them the beaten Argive division. |
[5.73.2] Meanwhile the Mantineans and their allies and the picked body of the Argives ceased to press the enemy, and seeing their friends defeated and the Spartans in full advance upon them, took to flight. |
[5.73.3] Many of the Mantineans perished; but the bulk of the picked body of the Argives made good their escape. The flight and retreat, however, were neither hurried nor long; the Spartans fighting long and stubbornly until the rout of their enemy, but that once effected, pursuing for a short time and not far. |