Very few literary works of Achaemenid Iran have survived, due partly to the destruction of the library at Persepolis. Most of what remains consists of the royal inscriptions of Achaemenid kings, particularly Darius I (522–486 BC) and his son Xerxes. Many Zoroastrian writings were destroyed in the Islamic conquest of Iran in the 7th century. The Parsis who fled to India, however, took with them some of the books of the Zoroastrian canon, including some of the Avesta and ancient commentaries (Zend) thereof. Some works of Sassanid geography and travel also survived, albeit in Arabic translations.