Cyaxares' Median Empire at the time of its maximum expansion.
Cyaxares was born in the Median capital of Ecbatana. His father Phraortes was killed in a battle against the Assyrians, led by Ashurbanipal, the king of Assyria. After Phraortes' demise, the Scythians overran Media. Cyaxares, seeking revenge, killed the Scythian leaders and proclaimed himself King of Medes. After throwing off the Scythians, he prepared for war against Assyria. Cyaxares reorganized the Median army, then allied himself with King Nabopolassar of Babylonia, a mutual enemy of Assyria. This alliance was formalized through the marriage of Cyaxares' daughter, Amytis, to Nabopolassar's son, Nebuchadnezzar II. These allies overthrew the Assyrian Empire and destroyed Nineveh in 612 BC.
War against Lydia
Qyzqapan tomb, likely relief of Cyaxeres (detail).
"A horde of the nomad Scythians at feud with the rest withdrew and sought refuge in the land of the Medes: and at this time the ruler of the Medes was Cyaxares the son of Phraortes, the son of Deïokes, who at first dealt well with these Scythians, being suppliants for his protection; and esteeming them very highly he delivered boys to them to learn their speech and the art of shooting with the bow. Then time went by, and the Scythians used to go out continually to the chase and always brought back something; till once it happened that they took nothing, and when they returned with empty hands Cyaxares (being, as he showed on this occasion, not of an eminently good disposition) dealt with them very harshly and used insult towards them. And they, when they had received this treatment from Cyaxares, considering that they had suffered indignity, planned to kill and to cut up one of the boys who were being instructed among them, and having dressed his flesh as they had been wont to dress the wild animals, to bear it to Cyaxares and give it to him, pretending that it was game taken in hunting; and when they had given it, their design was to make their way as quickly as possible to Alyattes the son of Sadyattes at Sardis. This then was done; and Cyaxares with the guests who ate at his table tasted of that meat, and the Scythians having so done became suppliants for the protection of Alyattes.
After this, since Alyattes would not give up the Scythians when Cyaxares demanded them, there had arisen war between the Lydians and the Medes lasting five years; in which years the Medes often discomfited the Lydians and the Lydians often discomfited the Medes (and among others they fought also a battle by night): and as they still carried on the war with equally balanced fortune, in the sixth year a battle took
place in which it happened, when the fight had begun, that suddenly the day became night. And this change of the day Thales the Milesian had foretold to the Ionians laying down as a limit this very year in which the change took place. The Lydians however and the Medes, when they saw that it had become night instead of day, ceased from their fighting and were much more eager both of them that peace should be made between them. And they who brought about the peace between them were Syennesis the Kilikian and Labynetos the Babylonian: these were they who urged also the taking of the oath by them, and they brought about an interchange of marriages; for they decided that Alyattes should give his daughter Aryenis to Astyages the son of Cyaxares, since without the compulsion of a strong tie agreements are apt not to hold strongly together." (The Histories, 1.73-74, trans. Macaulay)
In later accounts of the Hanging Gardens of Babylon, this was remembered as Nebuchadrezzar's present for his wife Amytis Cyaxares's daughter, to help with her homesickness for the mountainous country of her birth.
After Darius I seized the Iranshahr, rebellions erupted claiming Uvaxštra's legacy. After these were defeated, the shah noted two in the Behistun Inscription:
"Another was Phraortes [Fravartiš], the Mede [Mâda]; he lied, saying: 'I am Khshathrita, of the dynasty of Cyaxares.' He made Media to revolt. Another was Tritantaechmes [Ciçataxma], the Sagartian [Asagartiya]; he lied, saying: 'I am king in Sagartia, of the dynasty of Cyaxares.' He made Sagartia to revolt."
^ abGershevitch, I.; Fisher, William Bayne; Avery, Peter; Boyle, John Andrew; Frye, Richard Nelson; Yarshater, Ehsan; Jackson, Peter; Melville, Charles Peter; Lockhart, Laurence; Hambly, Gavin (1985). The Cambridge History of Iran. Cambridge University Press. p. 139. ISBN9780521200912.