Zoroastrianism, known of old as 'the Persian religion', is one of the world's most ancient prophetic faiths and one of Iran's great contributions to the history of religious thought. It is deeply rooted in the prehistoric Indo-Iranian and, ultimately, Indo-European tradition and thus shares a common heritage with the Vedic religion and Hinduism. In its long history it has influenced many other religions, notably Buddhism, Islam, Judaism and, especially, Christianity.
In the years after the Arab conquest of Iran in the 7th century, there was an exodus of Zoroastrians from Iran to the Indian subcontinent where they settled and became an influential minority under British colonial rule. The Parsis became renowned for their skill as entrepreneurs and generosity as philanthropists. Zoroastrians from both India and Iran have migrated to other parts of the world, especially Britain, the United States and Australia where they form diaspora communities today.