A fakir, or faqir (; (noun of faqr)), derived from faqr (, “poverty”), is a Muslim Sufi ascetic in the Middle East and South Asia. The Faqirs were wandering Dervishes teaching Islam and living on alms. The term has become a common Urdu, Bengali, and Hindi byword for beggar. Faqirs were Muslim ascetics and Sufis who have taken vows of poverty and worship, renounce all relations and possessions. Faqirs were characterised by their attachment to dhikr, (a practice of repeating the names of God, often performed after prayers) and asceticism. Sufism gained adherents among a number of Muslims as a reaction against the worldliness of the early Umayyad Caliphate (661–750 CE). Sufis have spanned several continents and cultures over a millennium, originally expressing their beliefs in Arabic, before spreading into Persian, Turkish, Indian languages and a dozen other languages. The term has also been used to refer to Hindu and Buddhist ascetics (e.g., sadhus, gurus, swamis and yogis). These broader idiomatic usages developed primarily in the Mughal era in India. Calanus, a Hindu Naga sadhu of the 4th Century B.C., is often called a faqir by historians. There is also a distinct clan of faqirs found in North India, descended from communities of faqirs who took up residence at Sufi shrines.