Leonidas was born around the year 540 BC in Sparta. Leonidas was the second son of King Anaxandridas II's first wife. Leonidas had two brothers: Dorieus, the eldest son of Anaxandridas's first wife, and Cleomenes, the son of the king's second wife. Because he was not expected to be king, Leonidas went through the harsh Spartan public school system in order to qualify for citizenship.
Rise to Power
When King Anaxandridas II died in 520 BC, Cleomenes became king. Dorieus was outraged by the decision because Cleomenes was the youngest son and Dorieus, the eldest. Dorieus left Sparta and attempted to start a colony in Africa and later in Sicily. Though he found success in Italy, he was killed soon after the colony's foundation. Leonidas remained in Sparta, marrying Cleomenes's daughter, Gorgo, in 490 BC. During Cleomenes's reign, the Greek states were at war with Persia, but before the war ended, Cleomenes was accused of insanity and fled Sparta in 490 BC. Leonidas succeeded Cleomenes as king, and when Persia invaded Greece again in 481 BC, Leonidas was chosen to lead the combined Greek forces.
Battle of Thermopylae
In August of 480 BC, Leonidas marched to Thermopylae with 300 Spartans. The other city-states of Greece sent additional troops, forming an army of about 14,000. There is some dispute over the reason for sending so few into battle, but most agree that it was because of the Olympic Games being held at the same time. Xerxes I, ruler of Persia, attacked the Greek army after five days of waiting. Leonidas and his men were able to hold of the Persians for the first two days, killing approximately 20,000 Persians while losing only 2,500 Greek soldiers. In the process, two of Xerces' brothers were killed.
On the seventh day of the Battle of Thermopylae, Ephialtes, a Greek traitor, led a group of Persians through a mountain pass to attack the Greeks from behind, When Leonidas found out, he sent away the entire Greek Army other than his 300 Spartans to keep them from being killed in the battle. 900 Helots and 700 Thespians, though, refused to leave Leonidas's side. Attacked from both the front and the back, Leonidas and his men held their post, but all were killed, though Spartans were able to recover Leonidas's body before the Persians could. Leonidas is on our list because he was both a tragic hero of the Ancient world, he also had a famous movie made about him.