Agis III was a king of Sparta who ruled during the 3rd century BC. He is best known for his efforts to restore the power and influence of Sparta after its decline following the Peloponnesian War. Agis III sought to implement reforms that would strengthen the Spartan economy and military. His reign was marked by conflict, particularly against the Achaean League and the Macedonian Empire. Agis III led a revolt against the Macedonian dominance in Greece but ultimately faced defeat at the Battle of Megalopolis in 331 BC, which led to the end of his reign and significant consequences for Sparta.