Cyrus has followed his conquest of Babylonia…

Cyrus has followed his conquest of Babylonia with campaigns against the nomads—called the Massagetae—living east of the Caspian Sea.

The details of Cyrus's death vary by account.

The account of Herodotus from his Histories provides the second-longest detail, in which Cyrus met his fate in a fierce battle with the Massagetae, a tribe from the southern deserts of Khwarezm and Kyzyl Kum in the southernmost portion of the steppe regions of modern-day Kazakhstan and Uzbekistan, following the advice of Croesus to attack them in their own territory.

The Massagetae are related to the Scythians in their dress and mode of living; they fight on horseback and on foot.

Cyrus, in order to acquire the realm, had first sent an offer of marriage to its ruler, Tomyris, a proposal she rejected.

He then commenced his attempt to take Massagetae territory by force, beginning by building bridges and towered war boats along his side of the river Jaxartes, or Syr Darya, which separated them.

Tomyris, sending him a warning to cease his encroachment, in which she stated she expected he would disregard anyway, challenged him to meet her forces in honorable warfare, inviting him to a location in her country a day's march from the river, where their two armies would formally engage each other.

He accepted her offer, but, learning that the Massagetae were unfamiliar with wine and its intoxicating effects, he set up and then left camp with plenty of it behind, taking his best soldiers with him and leaving the least capable ones.

The general of Tomyris's army, who was also her son Spargapises, and a third of the Massagetian troops, killed the group Cyrus had left there and, finding the camp well stocked with food and the wine, unwittingly drank themselves into inebriation, diminishing their capability to defend themselves, when they were then overtaken by a surprise attack.

They were successfully defeated, and Spargapises, who had been taken prisoner, committed suicide once he regained sobriety.

Tomyris, upon learning of what had transpired, denounced Cyrus's tactics as underhanded and swore vengeance, leading a second wave of troops into battle herself.

Cyrus the Great was ultimately killed, and his forces suffered massive casualties in what Herodotus referred to as the fiercest battle of his career and the ancient world.

When it was over, Tomyris ordered the body of Cyrus brought to her, then decapitated him and dipped his head in a vessel of blood in a symbolic gesture of revenge for his bloodlust and the death of her son.

Some scholars question this version, however, mostly because Herodotus admits this event was one of many versions of Cyrus's death that he heard from a supposedly reliable source who told him no one was there to see the aftermath.

Ctesias, in his Persica, has the longest account, which says Cyrus met his death while putting down resistance from the Derbices infantry, aided by other Scythian archers and cavalry, plus Indians and their elephants.

This event, according to Ctesias, took place northeast of the headwaters of the Syr Darya.

An alternative account from Xenophon's Cyropaedia contradicts the others, claiming that Cyrus died peaceably at his capital.

The final version of Cyrus's death comes from Berossus, who only reports that Cyrus met his death while warring against the Dahae archers northwest of the headwaters of the Syr Darya.