The existence of religious pluralism depends on the existence of freedom of religion. Freedom of religion is when different religions of a particular region possess the same rights of worship and public expression. Freedom of religion is consequently weakened when one religion is given rights or privileges denied to others, as in certain European countries where Roman Catholicism or regional forms of Protestantism have special status. Religious freedom has not existed at all in some communist countries where the state restricts or prevents the public expression of religious belief and may even actively persecute individual religions.
Religious pluralism has existed in the Indian Subcontinent since the rise of Buddhism around 500 BC and has widened in the course of several Muslim settlements (Delhi Sultanate1276-1526 AD and the Mughal Empire 1526-1857 AD). In the 8th century, Zoroastrianism established in India as Zoroastrians fled from Persia to India in large numbers, where they were given refuge. The colonial phase ushered in by the British lasted until 1947 and furthered conversions to Christianity among low caste Hindus. The rise of religious pluralism in the modern West is closely associated with the Reformation and the Enlightenment.
Religions like Judaism and Islam had existed alongside Christianity in many parts of Europe, but they were not allowed the same freedoms as the established form of Christianity. Freedom of religion encompasses all religions acting within the law in a particular region, whether or not an individual religion accepts that other religions are legitimate or that freedom of religious choice and religious plurality in general are good things.