The Battle of Tanagra was a land battle that took place in Boeotia in 457 BC between Athens and Sparta during the First Peloponnesian War. Tension between Athens and Sparta had built up due the rebuilding of Athens' walls and Spartan rejection of Athenian military assistance. The Athenians were led by Myronides and held a strength of 14,000. The Spartans were led by Nicomedes and had a total of 11,500 soldiers. While both the Athenians and Spartans suffered great losses, Sparta ultimately claimed victory in this battle.