Kleomenes I

Cleomenes I
King of Sparta
Reign	c. 519 BC – c. 490 BC
Predecessor	Anaxandrides II
Successor	Leonidas I
Died	c. 489 BC
Issue	Gorgo
Dynasty	Agiad
Father	Anaxandrides II

Cleomenes (/kliːˈɒmᵻniːz/; Greek Κλεομένης Kleomenes; died c. 489 BC) was an Agiad King of Sparta in the late 6th and early 5th centuries BC. During his reign, which started around 519 BC, he pursued an adventurous and at times unscrupulous foreign policy aimed at crushing Argos and extending Sparta's influence both inside and outside the Peloponnese. He was a brilliant tactician. It was during his reign that the Peloponnesian League came formally into existence. During his reign, he intervened twice successfully in Athenian affairs but kept Sparta out of the Ionian Revolt. He died in prison in mysterious circumstances, with the Spartan authorities claiming his death was suicide due to insanity.

He was the son of Anaxandrides II (of the Agiad royal house) and his second wife (apparently a daughter of Prinetades), and was the half-brother of Dorieus, Leonidas I, and Cleombrotus. Although the three younger half-brothers were the sons of Anaxandrides' first wife and therefore had a better claim to the throne according to tradition, Cleomenes was the oldest son and succeeded his father around 519 BC. He allowed his half-brother Dorieus to mount expeditions outside the Peloponnese, perhaps as a way of expanding Spartan influence and territories, and perhaps to rid himself of a potential rival. His interest in the world outside the Peloponnese may have accounted for some of his reputation for insanity among fellow Spartans who tended to be highly insular, conservative, and suspicious of all things foreign, especially that, according to Herodotus, Cleomenes acquired a taste for wine drunk "Scythian fashion" (unwatered).

...
Wikipedia