Wikipedia
Eucleidas
Eucleidas reigned Sparta from 227 BC to 222 BC. He was an Agiad, son of Leonidas II, in the place of the Eurypontid king.
His brother, Cleomenes III, deposed his Eurypontid colleague Archidamus V, and installed his brother as his new co-ruler.
According to Pausanias, Cleomenes poisoned Eurydamidas, his Eurypontid colleague, and shared the royal power with his brother Epicleidas.
Eucleidas was killed fighting against the Macedonians at the Battle of Sellasia (222 BC).