Cleomenes III was a king of Sparta who reigned from 235 to 222 BCE. He is known for his ambitious reforms aimed at revitalizing the Spartan state, which had been in decline. Cleomenes sought to redistribute land and reduce the power of the Gerousia, the council of elders, to strengthen the monarchy and improve the lives of the lower classes. His reign was marked by military campaigns against rival city-states, including Macedonia and Achaea. Cleomenes' efforts initially brought some success, but he ultimately faced defeat in the Battle of Sellasia in 222 BCE, leading to his downfall and the end of his reforms.