Reasons Behind Cyrus the Great’s Conquests

One of the most important aspects of Cyrus the Great’s actions that deserves examination is the reason behind his conquests. Historical studies point to the alliance of three powerful states—Lydia, Babylon, and Egypt—against Persia, with the intent to attack Cyrus’s domain, to which Cyrus responded accordingly.

First and foremost, it must be noted that the entire vastness of Cyrus’s empire did not result solely from his own conquests. Cyrus managed to bring the large territory of Media under his rule without a significant war. According to the Nabonidus Chronicle, the king of Media launched an attack on Cyrus with his army, but the Median troops rebelled against their king and handed him over to Cyrus (see: Nabonidus Chronicle, Column II, lines 1–2).

Given this event, Cyrus can be considered the legitimate ruler of Media. According to Greek historians, even his maternal grandfather was the former king of the Median Empire. Even if we set aside Cyrus’s familial ties with the Medes, it appears that the Medes accepted his kingship. The Median civilization had a significant impact on the Achaemenid Empire, and one can say that the Achaemenids were in many ways a continuation of the Medes.

Cyrus’s other conquests were also motivated by threats from foreign powers or alliances formed against him. If Cyrus had purely sought world domination, with the power he had accumulated, he could have easily conquered India, Egypt, and even all Greek-inhabited lands.

Hassan Pirnia wrote about the alliance of major regional powers against Iran during Cyrus’s time, stating that the conquest of Media caused anxiety among neighboring and even distant states. The three prominent powers of that era—Lydia, Babylon, and Egypt—entered into negotiations to form a triple alliance against Cyrus. Thus, Croesus, king of Lydia, Nabonidus, king of Neo-Babylon, and Amasis II, king of Egypt, allied themselves against Cyrus (Pirnia, 1983: p. 84).

This alliance of Cyrus’s enemies is confirmed in both Herodotus’s Histories and Xenophon’s Cyropaedia, making the account highly plausible (see: Herodotus, Book 1, 77 and 153; Xenophon, Book 2, 1:5).

In Xenophon’s Cyropaedia, this viewpoint also appears in Cyrus’s own words. Xenophon quotes Cyrus as saying:

Therefore, since you do not say anything, I will speak both for you and for ourselves. We are all agreed that, inasmuch as we are quite ready, it is best not to sit down here in a friendly country and wait till the enemy have invaded your territory before we begin to fight, but to go as quickly as possible into the enemy's country. (Xenophon, Book 3, 3:14)

Xenophon’s Cyropaedia places strong emphasis on Cyrus’s character and his strategic vision, particularly his defensive reasoning for military action. 

This idea of refraining from oppression against other nations also appears in the Cyrus Cylinder and the Nabonidus Chronicle. It seems Cyrus preferred to defeat his enemies without bloodshed whenever possible. Just as the Median soldiers joined him and brought the land of Media under his control, Cyrus aimed to avoid unnecessary violence.

Croesus, king of Lydia, initially intended to attack Cyrus, but even after his defeat, the threat to Cyrus remained. It was natural to fear a renewed alliance between Babylon and Egypt—two powers with a history of plotting against Persia. This time, however, internal unrest in Babylon led to its downfall.

It appears that certain figures inside Babylon invited Cyrus to intervene and end their chaotic conditions. This is suggested by the accounts of historians who mention a figure named Gobryas, who reportedly urged Cyrus to take Babylon. Regardless, the Cyrus Cylinder clearly illustrates Babylon’s dissatisfaction.

In what is likely the voice of a Babylonian narrator, it states:

"[Nabonidus] disrupted the offerings (to the temples). He tampered with the rites (in inappropriate ways), bringing sorrow and misery to the sacred cities.

He removed the worship of Marduk, king of the gods, from his heart. The one who constantly committed wrongdoing against his city (Babylon) and daily sought to harm the land, driving its people to ruin under a restless yoke.

In response to his anger, he (Nabonidus) brought the statues of the gods into Babylon. But Marduk, the exalted one who had decided to go to war, turned his attention toward all the inhabitants of the world whose homes had been ruined, and toward the people of Sumer and Akkad, who had become like lifeless corpses.

By his own will and mercy, Marduk turned toward them with compassion and forgave them. Among all the lands, he searched for a just king according to his heart—one whose hands he could hold. He called Cyrus, king of Anshan, by name and appointed him as king over all the world." (Cyrus Cylinder, lines 7–13)

The desire of the Babylonians to be liberated is clearly reflected in this inscription. Support for Cyrus seems entirely reasonable and also corresponds with the historical account involving Gobryas. Based on Babylonian records, Cyrus can be regarded as an accepted king of Babylon.

The presence of Scythian tribes—who were known for raiding other territories—may have prompted military campaigns in the eastern regions. Given these circumstances and the general conditions of that era, such actions would have appeared necessary for border security.

In conclusion, it should be said that Cyrus the Great, unlike Alexander, could have stormed India and Egypt, or—like many conquerors—pushed forward as far as possible. However, it seems Cyrus extended his borders only as far as was necessary to ensure the security of his realm, and he did not seek to conquer nations that posed no threat to his territorial integrity.