<P> The earliest reference to caste among Indian Christians comes from Kerala . Duncan Forrester observes that "Nowhere else in India is there a large and ancient Christian community which has in time immemorial been accorded a high status in the caste hierarchy...Syrian Christian community operates very much as a caste and is properly regarded as a caste or at least a very caste - like group ." Amidst the Hindu society, the Saint Thomas Christians of Kerala had inserted themselves within the Indian caste society by the observance of caste rules and were regarded by the Hindus as a caste occupying a high place within their caste hierarchy . Their traditional belief that their ancestors were high - caste Hindus such as Nambudiris and Nairs, who were evangelised by St. Thomas, has also supported their upper - caste status . With the arrival of European missionaries and their evangelistic mission among the lower castes in Kerala, two new groups of Christians, called Latin Rite Christians and New Protestant Christians, were formed but they continued to be considered as lower castes by higher ranked communities, including the Saint Thomas Christians . </P> <P> Caste system has been observed among Muslims in India . They practice endogamy, hypergamy, hereditary occupations, avoid social mixing and have been stratified . There is some controversy if these characteristics make them social groups or castes of Islam . </P> <P> Indian Muslims are a mix of Sunni (majority), Shia and other sects of Islam . From the earliest days of Islam's arrival in South Asia, the Arabic, Persian and Afghan Muslims have been part of the upper, noble caste . Some upper caste Hindus converted to Islam and became part of the governing group of Sultanates and Mughal Empire, who along with Arabs, Persians and Afghans came to be known as Ashrafs (or nobles). Below them are the middle caste Muslims called Ajlafs, and the lowest status is those of the Arzals . Anti-caste activists like Ambedkar called the Arzal caste among Muslims as the equivalent of Hindu untouchables, as did the controversial colonial British ethnographer Herbert Hope Risley . </P> <P> In Bengal, some Muslims refer to the social stratification within their society as qaum (or Quoms), a term that is found among Muslims elsewhere in India, as well as in Pakistan and Afghanistan . Qaums have patrilineal hereditary, with ranked occupations and endogamy . Membership in a qaum is inherited by birth . Barth identifies the origin of the stratification from the historical segregation between pak (pure) and paleed (impure) - - defined by the family's social or religious status, occupation and involvement in sexual crimes . Originally, Paleed / Paleet qaum included people running or working at brothels, prostitution service providers or professional courtesan / dancers (Tawaif) and musicians . There is history of skin color defining Pak / Paleed, but that does not have historical roots, and was adopted by outsiders using analogy from Hindu Caste system . </P>

In india the caste system is based on what