Battle of Mantinea

The First Battle of Mantinea of 418 BC was a significant engagement in the Peloponnesian War. Sparta and its allies defeated an army led by Argos and Athens.

After the conclusion of the alliance between the Argives, Achaeans, Eleans, and Athens, the defeat of the Spartans in the Olympic Games of 420 B.C. and the invasion of Epidaurus by the allies, Sparta chose to move against them, fearing their potential alliance with Corinth. The army that was amassed for this purpose was, according to Thucydides, 'the best army ever assembled in Greece to that time'. However, the Spartan king Agis instead concluded the first campaign with a truce, without explaining his actions to the army or his allies. Immediately afterwards, the Argives denounced the truce and resumed the war, capturing the key town of Orchomenus. As a result, Spartans directed their anger towards Agis, who narrowly avoided a 100,000 drachmas fine and the destruction of his house. Agis managed to forestall this punishment, promising to redeem himself with a victory elsewhere. The ephors consented, but in an unprecedented move, placed Agis under the supervision of ten advisors, called symbouloi, whose consent was required for whatever military action he wished to take.

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