Avesta: the holy book of Zoroastrianism, the Iranian religion that was founded by the legendary Bactrian prophet Zarathustra.

Faravahar, the visual aspect of Ahuramazda. Relief from Persepolis.

Like the Bible, the Avesta (sometimes incorrectly called Zend-Avesta) is actually a library, containing different sacred texts which were written during a very long period in different languages. A difference with the Bible is that the Avesta often resembles a prayer book and has few narratives.


The seventeen Gâthâs, probably composed by Zarathustra himself, are the oldest part of the Avesta (overview). The language of these hymns resembles that of the Indian Rigveda, hymns that were probably composed in the Punjab between 1500 and 1200 BCE. E.g., the Gathic word ahura, "divine lord", is identical to the Vedic word asura. This linguistic similarity suggests that the Gâthâs are very old indeed.

In the Gâthâs, Zarathustra addresses the supreme god Ahuramazda, which offers the prophet an opportunity to explain his own doctrines. An example:

I shall recognize Thee as strong and holy, Ahuramazda, when Thou wilt help me by the hand with which Thou holdest the recompenses that Thou wilt give, through the heat of Thy truth-strong fire, to the wicked man and the just - and when the might of Good Purpose shall come to me.
Then as holy I have recognized Thee, Ahuramazda, when I saw Thee as First at the birth of life, when Thou didst appoint rewards for acts and words, bad for the bad, a good recompense for the good by Thy innate virtue, at the final turning point of the creation [i.e., the Last Judgment].note

It should be stressed that the Gâthâs are difficult to understand. They were written long time ago in an otherwise unknown dialect. To understand what Zarathustra intended to convey, we have two methods:

Both approaches are dangerous. The Vedic and Gathic languages have a common ancestor, but developed differently. As we have already seen above, Gathic ahura meant "divine lord"; Vedic asura meant "demon". It is probably no coincidence that the reverse also happens to be true: the Vedic word for "gods", deva, means "demons" in Gathic (daeva). It may be assumed that the two languages parted because of a religious dispute, which makes linguistic comparisons difficult.

The use of younger parts of the Avesta to explain the older parts is equally dangerous. Some of these texts are clearly written to explain something that was no longer understood. The explanations are, therefore, nothing but hypotheses of a venerable age. Unfortunately, we are unable to check these interpretations and therefore, several European scholars have argued that it is better not to explain the Gâthâs by using younger texts. Perhaps this is a bit too skeptical, but the risks of the method are real.


There are other hymns that are attributed to Zarathustra. These Yashts are dedicated to lower gods. However, it is almost certain that these hymns were not really composed by the prophet, because they are written in another language, which is usually called "Younger Avestan". This language resembles the Old Persian that we know from the cuneiform texts of the Achaemenid Empire written between 521 and 331 BCE. The composition of the Yashts may therefore tentatively be dated between, say, 625 and 225.


The Gâthâs were (and are) recited by the Zoroastrians in their daily liturgy. The liturgical texts, usually called Yasna ("reverence"), were also written in Gathic; at least some of them appear to be older than the Gâthâs, and may have been reworked in the light of the teachings of Zarathustra. The Yasna describes all kinds of rituals, e.g., the use of the trance-inducing beverage haoma, sacrifices, and offerings to water and fire. Over the centuries, new liturgic texts were written; these are written in Younger Avestan.


The next group of texts is called the Vendidad. This word is a corruption of Vidaevadata, "against the demons". The language of these prose texts, which deal with myth and purity laws, is Younger Avestan, but it does not resemble the language of the cuneiform texts of the Achaemenid Empire. Probably, the Vendidad was written later, during the Parthian period (141 BCE - 224 CE).

Parthian codification

It may have been only at this stage that the texts of the Avesta were collected, but the date of this first redaction is very uncertain. Some scholars have denied that there was a redaction at the Parthian time; others maintain that there was an even earlier redaction in the Achaemenid period. The excellent transmission of the Gâthâs suggests that there must have been some sort of written version, but we do not know what this can have been. In any case, the name "Avesta" was coined in the Parthian age, because âbâsta, "the law", is Parthian Younger Avestan.

Although we do not know when the texts were brought together, we may be confident that there was a large religious literature. This can be deduced from a remark by the Roman author Pliny the Elder (23-79 CE), who writes about the Alexandrine scholar Hermippus of Smyrna (third century BCE):

Hermippus, who wrote most painstakingly about the whole art of magic and interpreted two million verses by Zarathustra, also added lists of contents and handed down the name of Agonaces as the teacher who instructed him, placing Zarathustra five thousand years before the Trojan War.note

In other words: at some point in history, perhaps the Parthian age, many ancient texts were brought together:

These were the main parts of the Avesta, but there must have been other texts. For example, we possess late versions of apocalyptic texts that go back to texts that were composed towards the end of the fourth century BCE, when the Macedonian king Alexander the Great conquered the Achaemenid Empire.


In 224 CE, the Parthian rulers of Iran were replaced by a new Persian dynasty, the Sasanians. Other texts were added to the already existing corpus, the most important being the Visperad, a long liturgy made up from Yasna and Vendidad texts with many additional invocations. Another texts is the Khorda Avesta or "Short Avesta", a collection of short prayers that could be used by every believer. The language of this period is known as Middle Persian or Pahlavi.

Sasanian codification

Several Sasanian kings were devout Zoroastrians and did much to improve the understanding of the ancient texts. The text known as Denkard, which we will discuss below, mentions a collection made for king Shapur I (r.241-272). There were also several commentaries on the Avesta, the Zand. They became an integral part of the Avesta; every copy of the original text contained the Zand as well.note

Khusrau II

Under the Sasanian king Khusrau II the Victorious (r.591-628), a Zoroastrian high priest named Tansar established the canon of Avestan texts. It contained all the texts that we have already seen, but also some books on cosmogony and law, a biography of Zarathustra, apocalypses, and several expositions of doctrine. This library was certainly written down and is called the Great Avesta.

The Middle Ages

The Great Avesta was too large to survive, especially since invading armies sometimes destroyed the books. In 642, the Arabs invaded Iran. As a rule, they were not intolerant towards Zoroastrianism and some Avestan works were translated into Arabic, the originals being lost. In the eighth century, however, relations between Muslims and Zoroastrians became hostile and the Zoroastrians started to redefine themselves: their ancient religion and old language were important aspects of their new self-image. The antagonism between the two groups continued to grow in the ninth century. Many Zoroastrians decided to migrate to India. Several texts from the Avesta are therefore known from Indian translations.

Between 1037 and 1157, the Seljuk Turks ruled Iran. Harshness towards non-Muslims increased, but it was nothing compared to the events of 1256, when the Mongol leader Hulagu, a grandson of Genghis Khan,  invaded Iran, Iraq, and Syria. For the first time, Zoroastrianism was actually persecuted, and many books were burnt. This was repeated in 1381, when Timur Lenk invaded and ravaged Persia. The Zoroastrians were forced to withdraw to desert towns like Yazd and Kerman.

From 1501 onward, Iran was independent under the dynasty of the Safavids. Their kings were Shi'ite Muslims and were in general harsh towards Zoroastrians. The latter were even forced to conversion by Shah Abbas II (r.1642-1667), who had many of them massacred in Isfahan. Again, many Avestas were destroyed.


What remains of the Avesta today, is about a quarter of the Great Avesta of the sixth century. Fortunately, we do possess a summary, which is called the Denkard (go here to read  a chapter). Using the Denkard, the Zand, and the traditions of medieval Zoroastrianism, we can reconstruct large parts of the Great Avesta. However, this reconstruction is necessarily hypothetical, and as we have seen above, some European scholars have decided that these texts are not very useful - except, of course, for the study of Medieval Zorastrianism. This is a little bit too skeptical: the Denkard and the Zand contain some very ancient traditions. On the other hand, one should be very careful when one studies a complex library like the Avesta.