Freedom of religion is a principle that supports the freedom of an individual or community, in public or private, to manifest religion or belief in teaching, practice, worship, and observance without government influence or intervention. It also includes the freedom to change one's religion or belief.
Freedom of religion is considered by many people and most of the nations to be a fundamental human right. In a country with a state religion, freedom of religion is generally considered to mean that the government permits religious practices of other sects besides the state religion, and does not persecute believers in other faiths. Freedom of belief is different. It allows the right to believe what a person, group or religion wishes, but it does not necessarily allow the right to practice the religion or belief openly and outwardly in a public manner.
Historically, freedom of religion has been used to refer to the tolerance of different theological systems of belief, while freedom of worship has been defined as freedom of individual action. Each of these have existed to varying degrees. While many countries have accepted some form of religious freedom, this has also often been limited in practice through punitive taxation, repressive social legislation, and political disenfranchisement. Compare examples of individual freedom in Italy or the Muslim tradition of dhimmis, literally "protected individuals" professing an officially tolerated non-Muslim religion.
In Antiquity, a syncretic point of view often allowed communities of traders to operate under their own customs. When street mobs of separate quarters clashed in a Hellenistic or Roman city, the issue was generally perceived to be an infringement of community rights.
Cyrus the Great established the Achaemenid Empire ca. 550 BC, and initiated a general policy of permitting religious freedom throughout the empire, documenting this on the Cyrus Cylinder.