The Lelantine War was a military conflict between the two ancient Greek city states Chalcis and Eretria in Euboea which took place in the early Archaic period, between c. 710 and 650 BC.

Due to the economic importance of the two participating poleis, the conflict spread considerably, with many further city states joining either side, resulting in much of Greece being at war.

The foundation stories of the joint Euboean colony at Ischia suggest that at the mid-8th century Chalcis and Eretria were cooperating.

[6] Since the conflict took place at a very early point in Greek history, before historiography had developed, there are no contemporaneous written sources on the events.

However, as a result of the ambiguity of the surviving written sources, date and extent of the war are disputed among Classical scholarship.

According to Plutarch, Kleomachos himself was killed during the battle and received an honourable burial as well as a commemorative column on the agora of Chalcis from her grateful citizens.

(...) Kleomachos, being surrounded with some few of the flower of the Thessalian horse, he charged into the thickest of the enemy and put them to the rout; which the heavy-armed infantry seeing, they betook themselves also to flight, so that the Chalcidians obtained a noble victory.

Plutarch states that Amphidamas fell in the struggle for the Lelantine Plain, after performing several heroic deeds fighting the Eretrians.

This Amphidamas was a leading citizen, one that had perpetual wars with the Eretrians, and at last lost his life in one of the battles fought for the possession of the Lelantine plain.Plutarch's source was traditionally attributed to Hesiod himself.

Then I crossed over to Chalkis, to the games of wise Amphidamas where the sons of the great-hearted hero proclaimed and appointed prizes.In his Geographica, Strabo (c. 63 BC to 23 AD) reports that the two poleis, Chalcis and Eretria had once been friendly.

He states that their former friendship resulted in both parties to the conflict agreeing before battle on contractually determined conditions, especially on not using missiles.

Not many bows will be drawn, nor will slings be common, whenever battle will be joined in the plain; instead the much-sighing work will belong to the swords, for the warlike lords of Euboea are experienced in that manner of war.On the basis of these literary sources, and assisted by a variety of archaeological finds, modern scholarship has reconstructed an outline of the Lelantine War.

[10] The site of Chalcis, still occupied, has been subject to very little archaeological research, but similar burials of warriors are indicated by written sources, especially in reference to Amphidamas.

[11] Around 680 BC, a triangular building was erected atop the warrior graves at Eretria and used to dedicate offerings to the fallen heroes.

[15] The two leading powers of the island, Chalcis and Eretria were among the driving forces behind the apoikiai of the Mediterranean, acting for a long time not as competitors but as collaborators.

Since the second quarter of the 8th century, Euboean traders were present on the island of Pithekoussai (Ischia) off the coast of Campania, to conduct trade with the Etruscans.

In Greece, where fertile land is scarce, wars for agriculturally attractive terrain were not uncommon, especially in the Archaic period, e.g. between Megara and Athens.

[18] Nevertheless, it remains unclear why Chalcis and Eretria suddenly came to blows over the Lelantine Plain after apparently being in agreement on its use for a long time.

[21] Since the war took place before the development or introduction of hoplite warfare, but under exclusion of bows and slings,[22] most of the combatants were probably lightly armed swordsmen.

This implies that this conflict took place at the transitional time between the Homeric aristos, entering the war on chariot and fighting his enemies like the heroes of the Iliad, and the classical hoplite.

At the time of the war, the state of Eretria included one quarter of the island of Euboea as well as the nearby Cyclades (Andros, Tenos, and Kea).

Beyond these, the enmities and alliances between Archaic Greek states known from other sources have led to further suggestions of parties involved, leading some scholars to propose up to 40 participants.

Instead, there may have been alliance-like based on personal relationships among the nobility, so that the struggle involved only Eretria, Chalcis and the Thessalian aristocrat Kleomachos of Pharsalos with his own troops.

[7] The German historian Detlev Fehling believes that the entire Lelantine War is an invention of later centuries, produced by a chain of Pseudo-Nachrichten (pseudo-reports).