The "Book of Arda Wiraz", a Zoroastrian work composed in the 3rd or 4th century, describes Persepolis' archives as containing "all the Avesta and Zend, written upon prepared cow-skins, and with gold ink", which were destroyed. Indeed, in his "Chronology of the Ancient Nations", the native Iranian writer Biruni indicates unavailability of certain native Iranian historiographical sources in the post-Achaemenid era, especially during the Parthian Empire. He adds: " burned the whole of Persepolis as revenge to the Persians, because it seems the Persian King Xerxes had burnt the Greek City of Athens around 150 years ago. People say that, even at the present time, the traces of fire are visible in some places."