Zoroastrianism in India  Zoroastrianism in India has significant history within the country. The initial migration following the Muslim conquest of Persia has been canonized as a religious persecution by invading Muslims. Zoroastrianism meanwhile suffered a decline in Iran after the conquests. Subsequent migrations also took place after the attempts by Safavids to convert their subjects to Shiism. Due to persecution of Zoroastrians in other countries and the liberal atmosphere and patronisation of India, today the largest population of Zoroastrians resides in India, where Zoroastrians have been allowed to play a notable role in the Indian economy, entertainment, the armed forces, and the Indian freedom movement during British Raj. The Zoroastrian groups are regarded as either Parsi or Irani depending on the time of migration to India. By 632 A.D., Yazdgird III came to power in Iran but the Arab/Muslim army had already begun invading Iran. The Muslims defeated them at Nahavand and Yazdgird was slain by a miller in Merv in 652, bringing an end to the Sasanian dynasty and thus of the official history of Zoroastrian Iran. While losing their religion and script along with some Sasanian historiographical literature, the language and culture essentially survived. Between the seventh and thirteenth century, political and social pressures resulted in ascendancy of Iranian Muslim over the Zoroastrians. With the conquests, Iranians gradually lost their predominant religion. The Zoroastrians moved to India in successive migrations in the Islamic period. According to the account, the Zoroastrians suffered at their hands and in order to protect themselves and safeguard their religion, fled first to northern Iran, then to the island of Hormuz and finally to India. Recently, scholars have questioned this explanation of Iranian origins. There is a scarcity of sources about the migration. Historians are forced to rely exclusively on "Qissa-i Sanjan" written in 1599 by a Parsi Priest and "Qissah-ye Zartushtian-e Hindustan" written more than 200 years later. This is complicated by the fact that there were already Zoroastrians in India in the Sasanian period. Iranian Zoroastrians are known to have been trading with India for centuries before the dates calculated for arrival of Parsis per Qissa-i Sanjan. Ruksana Nanji and Homi Dhalla while discussing archaeological evidence for 'The Landing of Zoroastrians at Sanjan', conclude that the most likely date for the migration at the start of the middle phase of their chronology, namely the early-to-mid-eighth century.