Were the Achaemenids Zoroastrians?

Before the arrival of Islam Zoroastrianism was the dominant religion of Greater Iran. Because of the predominance of Zoroastrianism it has often been assumed that all pre-Islamc Iranian dynasties had been Zoroastrians. This notion, however, has been called into doubt by recent scholarship. Scholars see too many contradictions between the religion of the Achaemenids (the first Persian dynasty, r. 550-330 BC) and ‘true’ Zoroastrianism. In order to settle the matter, we need to determine what exactly ‘true Zoroastrianism’ is.

Zarathustra as depicted on Rafael's 'School of Athens' (1509).
Zarathustra as depicted on Rafael’s ‘School of Athens’ (1509).

What is Zoroastrianism?
The religion that we call Zoroastrianism today did not reach its definitive form until the Sasanid period, when Persian priests tried to define their traditional beliefs in opposition to other organized religions, like Judaism, Christianity and Buddhism. Unlike these religions, the traditional religion of the Persians did not yet have central doctrines and until the Sasanid period it had been very diverse. The Persians and other Iranian peoples did have sacred ‘texts’; mostly hymns and ceremonial instructions that were passed down orally from generation to generation. A wide variety of holy texts circulated among the Iranian peoples and it wasn’t until the Sasanid period that some of these texts were canonized, codified and eventually written down. One might therefore say that one cannot speak of Zoroastrianism before the Sasanid period. But then again, this is too simplistic. The Iranian peoples did have common beliefs, practices and holy texts that separated them from the rest. Most of these holy texts were attributed to a certain Zarathustra, a prophet about whom not much is known but who apparently brought a new message to the Iranian peoples.

Who was Zarathustra?
What exactly was the message of this Zarathustra? We have no sources about his life, other than the hymns that are, often controversially, attributed to him and biographies that were written much, much later. The texts most often attributed to Zarathustra are the Gatha’s, a collection of songs in which Zarathustra praises the god Ahura Mazda, renounces an evil metaphysical entity known as ‘the Lie’ and encourages his followers to serve Truth, to think Good Thoughts, to speak Good Words and to do Good Deeds. Zarathustra also renounces a category of gods known as the daeva’s and the practice of animal sacrifice. The language in which these Gatha’s were spoken, known as Old Avestic, has been estimated by linguists to date back to 1400 to 1200 BC. Another important category of texts that has traditionally been attributed to Zarathustra are the Yashts, a collection of hymns that praise several gods and metaphysical concepts and make references to stories from Iranian mythology. The fact that the Yashts praise other gods beside Ahura Mazda (many gods, like Anahita, Tishtrya, Drvaspa, Mithra, Rashnu, the Fravashis, Verethragna, Vayu, Ashu and Zam, even have more hymns than Ahura Mazda) and that animal sacrifice is explicitly mentioned in them may be used as an argument against authorship by Zarathustra. An even better argument is that these Yashts were written in a dialect of Avestic that is at least 500 years younger than the Avestic of the Gatha’s. Perhaps the Yashts were composed by priests who were followers of Zarathustra, or perhaps they weren’t followers of Zarathustra at all, but their hymns eventually got associated with Zarathustra’s teachings.

Were the Achaemenids Zoroastrians? – Arguments in favor of the thesis
Now let us look at the religion of the Achaemenids. The Achaemenids were the first Iranian dynasty to found a true empire. Nevertheless, the Achaemenids aren’t necessarily known for their assertive promotion of Iranian culture. On the contrary, they borrowed much of their cultural and administrative practices from the peoples they had conquered, like the Elamites and the Babylonians. Although not much is known about the religion of Cyrus the Great, we do know that he offered an (animal) sacrifice to the Babylonian supreme god Marduk. Darius the Great and his descendants express their Iranian heritage more openly. First of all, Darius the Great calls himself an ‘Aryan’ (i.e. Iranian) in his Bisotun inscription and in all of his inscriptions he makes it clear that he worships the god Ahura Mazda as his personal patron. He also portrays ‘the Lie’ as a metaphysical entity that seeks to destroy the order created by Ahura Mazda. Darius presents himself as the one who was chosen by Ahura Mazda to establish divine order on earth. This belief is similar to Assyrian and Babylonian concepts of kingship and also runs parallel to early Jewish messianism. In addition, Darius’s son Xerxes claims to have destroyed the sanctuaries of the daeva’s, the evil gods renounced by Zarathustra. Considering all these similar beliefs and practices, it seems that the Achaemenids, at least from Darius onward, were Zoroastrians.

Darius's inscription at Bisotun. In this inscription Darius refers to Ahura Mazda as his personal god.
Darius’s inscription at Bisotun. In this inscription Darius refers to Ahura Mazda as his personal god.

Were the Achaemenids Zoroastrians? – Arguments agains the thesis
There are also many reasons to assume that the Achaemenids were not Zoroastrians, or at least not very orthodox. As can be deduced from the Persepolis Fortification Archive, many gods beside Ahura Mazda were worshiped at the Persian court. In fact, most sacrifices were dedicated to the Elamite god Humban. This isn’t necessarily a problem, since even the Gatha’s do not reject the worship of other gods. Only the daeva’s are to be shunned (whoever they may be). Furthermore, the Yashts also openly praise other gods. Another argument against the idea that the Achaemenids were not Zoroastrians is that the Achaemenid kings were buried, whereas in orthodox Zoroastrianism the bodies of the dead are exposed in the open air to birds of prey. This is because burying or cremating the body would pollute the sacred earth or the sacred fire. However, as I mentioned before, it is not right to speak of Zoroastrian orthodoxy before the Sasanid period. The religious beliefs and practices of the Iranians were probably very diverse during the Achaemenid period. The best argument against the idea that the Achaemenids were Zoroastrians is that many of the ‘Zoroastrian’ concepts promoted by the Achaemenids, like the worship of Ahura Mazda or the rejection of ‘the Lie’ and the daeva’s were not exclusive to the teachings of Zarathustra and may instead date back to a common proto-Iranian religion. In order to determine whether or not the Achaemenids were Zoroastrians, we therefore need to determine up to what extent the ideas expressed by them were unique to Zoroastrianism.

The Iranian family of languages
In order to truly understand the significance of Zarathustra’s teachings, we need to look at their cultural context. The books of the Avesta were composed in Avestic, an Eastern Iranian language that was spoken roughly between 1400 and 400 BC. The region where this language was spoken has not been identified with certainty, but it probably was outside the borders of modern Iran. Both Afghanistan and Uzbekistan are plausible candidates. The Avestic language was closely related to that of other Eastern Iranian peoples, like the Scythians, the Saka, the Sarmatians and the Alans. Probably the Avestic people were the sedentary counterparts of these nomadic peoples. These Eastern Iranian languages were descended from a proto-Iranian language that was spoken around 2000 BC. Somewhere between 2000 and 1400 BC (let’s say 1700 BC for the sake of convenience) the proto-Iranian language split up into an Eastern and a Western branch. The Medes and the Persians belong to the Western branch; the Avestic people and the Scythians, Saka, Sarmatians and Alans belong to the Eastern branch. The Medes and the Persians most likely split off before the Gatha’s were composed, since the latter were spoken in an Eastern Iranian dialect. If the Medes and the Persians were Zoroastrians, they must have acquired this religion from the Eastern Iranians. The question that needs to be answered is: “Were Darius’s religious ideas derived from the beliefs of the Avestic people, or were they derived from a common proto-Iranian religion.”

Indo-Iranian family tree
Indo-Iranian family tree

The proto-Iranian religion
In order to understand the proto-Iranian religion we again need to look at its cultural context. Proto-Iranian has a common ancestor with proto-Indo-Aryan, the language of the peoples of Northern India. This language, known as proto-Indo-Iranian, was spoken before 2000 BC on the Kazakh steppes by a people who called themselves ‘Aryans’. These Aryans worshiped a wide variety of gods. They even had categories of gods, like the deva’s, who represented natural powers, and the asura’s, who represented metaphysical concepts. They worshiped their gods mainly through animal sacrifice and also had a ritual in which they used a psychedelic substance known as soma. Around 2000 BC the Indo-Aryan branch split off and started migrating south, to the Oxus river valley, and from there to Afghanistan, Pakistan and Northern India. These Indo-Aryans mainly worshiped the deva’s and shunned the asura’s. The religion of these Indo-Aryans is recorded in the Veda’s, the sacred texts of the Hindus. In the meanwhile the Iranian branch stayed put on the steppes. Little is known about the proto-Iranian religion due to the lack of sources. When trying to reconstruct the proto-Iranian religion, scholars often look towards the Eastern Iranian Avesta or the Western Iranian Achaemenid inscriptions. However, they tend to overlook the nomadic Eastern Iranians who stayed put on the steppes and probably preserved much of the original proto-Indo-Iranian religion. Although we do not know much about the religion of the Scythians, Saka, Sarmatians and Alans, Herodotus claims that they worshiped many gods that were unknown among either the Avestic people or the Achaemenids. There is no evidence that they worshiped Ahura Mazda or any other major god mentioned in the Avesta and they also enthusiastically participated in animal and even human sacrifice. At first glance these nomadic Eastern Iranians had a very different religion than either the Avestic people or the Achaemenids, which indicates that many ‘Zoroastrian’ principles, like the worship of Ahura Mazda or the rejection of the Lie, the daeva’s and animal sacrifice, were indeed innovations that happened among the Avestic people and were later borrowed by (some of the) Western Iranians. In this respect one could say that the Achaemenids were indeed Zoroastrians.

A tentative reconstruction
Starting from this conclusion, let us now reconstruct the religious history of the Iranians from proto-Indo-Iranian times up to the Achaemenid period.

  • Before 2000 BC the Aryans lived on the Kazakh steppes. They had a religion with many gods who were subdivided into categories, they practiced animal sacrifice, used soma and they likely glorified warfare.
  • Between 2000 and 1700 BC the Aryans split up into two branches. The Indo-Aryan branch migrated south towards the Oxus river valley and settled among the sedentary population. The Iranian branch stayed put on the Kazakh steppes. Both branches were still had very similar religious beliefs and practices.
  • Between 1700 and 1400 BC some Indo-Aryans spread to Afghanistan, Pakistan and Northern India. Those who migrated started worshipping the deva’s and shunning the asura’s. The Iranian branch stayed put on the steppes and split into a Western and an Eastern branch.
  • Between 1400 and 1200 BC the deva-worshipping Indo-Aryans of the Punjab region composed the Veda’s. At the same time some Eastern Iranian tribes settled in present day Uzbekistan and Afghanistan, where deva-worshipping Indo-Aryans were probably still dominant. These sedentary Eastern Iranians were the Avestic people. Some Avestic people started worshipping the deva’s, but they were opposed by Zarathustra, who shunned the deva’s, rehabilitated the asura’s (ahura’s in Avestic) and promoted the worship of Ahura Mazda. He also banned animal sacrifice and other violent practices of the Aryan people. The Gatha’s date to this time.
  • Between 1200 and 1000 BC the Western Iranian peoples, ancestors of the Medes and the Persians, migrated from the steppes, through lands inhabited by the Avestic people, to the Zagros Mountains. On the way they interacted with the Avestic people and borrowed some of their religious ideas and practices, like the cult of Ahura Mazda, the rejection of the daeva’s and the religiously sanctioned moral code. They did not give up animal sacrifice.
  • Between 1000 and 550 BC the Yashts and other Avestic texts were written down by the late Avestic people. These works did not influence the Medes and the Persians. In the meanwhile the Medes and the Persians settled in the Zagros Mountains and adopted many local gods.
  • During the Achaemenid period the Persians had likely been influenced to some extent by ideas originating in the ‘Zoroastrian reforms’. However, one could say that they followed a different form of Zoroastrianism that the late Avestic people. Later, probably during the Parthian period (141 BC – AD 224), the traditions and holy texts of the Avestic people spread across Greater Iran and were adopted by the Persians before the Sasanid period commenced.Faravahar

Further reading
If you want to learn more about Zoroastrianism in general, Peter Clark’s Zoroastrianism – An Introduction to an Ancient Faith (1998) is a good starting point. If you want to make up your own mind on this issue whether or not the Achaemenids were Zoroastrians, here are two works from both sides of the debate that in my opinion make the best case for their respective points of view:

Henkelman, W.F.M. (2008): Achaemenid History Volume 14; The Other Gods Who Are.

Jong, A.F. de (2015): ‘Religion and politics in pre-Islamic Iran’ in M. Stausberg, Y. Sohrab-Dinshaw & A. Tessman (eds.) The Wiley Blackwell Companion to Zoroastrianism.