Battle of Sepeia

At the Battle of Sepeia (494 BC), the Spartan forces of Cleomenes I defeated the Argives, fully establishing Spartan dominance in the Peloponnese. The closest thing to a contemporaneous source for the description of the battle is, as for many events in this time period, the Histories of Herodotus (written approximately fifty years later, c. 440 BC). According to Herodotus, the Spartan army tricked the Argives into believing that the Spartans were going to their evening meal, and when the Argives did the same, the Spartans seized up their arms and attacked them, gaining an overwhelming victory. The battle is a controversial one in terms of the Spartan legend for, according to Herodotus, Spartan King Cleomenes massacred the remaining Argives—most by burning them alive in the sacred grove of Argos to which they had fled for refuge.