Cleomenes was a king of Sparta who ruled during the early 3rd century BCE. He is best known for his military campaigns against Macedonia and his efforts to reform the Spartan government. Cleomenes aimed to restore the traditional Spartan way of life and strengthen the city-state's power. His reign was marked by significant conflicts, including the Battle of Sellasia in 222 BCE, where he faced the forces of Antigonus III Doson. Despite initial successes, Cleomenes ultimately faced defeat and fled to Egypt, where he spent the remainder of his life in exile.