any of the units of social stratification that developed among Muslims in India and Pakistan as a result of the proximity of Hindu culture. Most of the South Asian Muslims were recruited from the Hindu population; despite the egalitarian tenets of Islam, the Muslim converts persisted in their Hindu social habits. Hindus, in turn, accommodated the Muslim ruling class by giving it a status of its own.

In South Asian Muslim society a distinction is made between the ashrāf (Arabic, plural of shārīf, “nobleman”), who are supposedly descendants of Muslim Arab immigrants, and the non-ashrāf, who are Hindu converts. The ashrāf group is further divided into four subgroups: (1) Sayyids, originally a designation of descendants of Muhammad through his daughter Fāṭimah and son-in-law ʿAlī, (2) Shaykhs (Arabic: “Chiefs”), mainly descendants of Arab or Persian immigrants but also including some converted Rājputs, (3) Pashtuns, members of Pashto-speaking tribes in Afghanistan and northwestern Pakistan, and (4) Mughals, persons of Turkish origin, who came into India with the Mughal armies.

The non-ashrāf Muslim castes are of three levels of status: at the top, converts from high Hindu castes, mainly Rājputs, insofar as they have not been absorbed into the Shaykh castes; next, the artisan caste groups, such as the Julāhās, originally weavers; and lowest, the converted untouchables, who have continued their old occupations. These converts of Hinduism observe endogamy in a manner close to that of their Hindu counterparts.

Two of the principal indexes of Hindu caste, commensality and endogamy (principles governing eating and marital arrangements), do not appear as strongly in Islamic castes. Commensality is prohibited between ashrāf and non-ashrāf, between Muslim and Hindu, and between the various castes of the non-ashrāf. The principle of endogamy is altered by the Muslim preference of marriage within very narrow limits (e.g., to the daughter of the father's brother), which in South Asia is known as biyāhdārī.