The word Dervish, especially in European languages, refers to members of Sufi Muslim ascetic religious fraternities, known for their extreme poverty and austerity, similar to mendicant friars.
The term comes from the Persian word Darvish (درویش), which usually refers to a mendicant ascetic. This latter word is also used to refer to an unflappable or ascetic temperament (as in the Urdu phrase darwaishana thabiyath for an ascetic temperament); that is, for an attitude that is indifferent to material possesions and the like.
As Sufi practitioners, dervishes were known as source of wisdom, medicine, poetry, enlightment, and witticisms. For example, Mollah Nasr-ad-Din (Mulla Nasrudin, Hoja Nasrudin) had become a legend in the Near East and the Indian subcontinent (and not only Muslims).
Many of the dervishes are mendicant ascetics who have taken the vow of poverty. Though some of them are beggars by choice, others work in common professions; Egyptian Qadirites, for example, are fishermen.
There are also various dervish fraternities Sufi orders, almost all of whom who trace their origins from various Muslim saints and teachers, especially Ali and Abu Bakr. They live in monastic conditions, superficially similar to Christian monk fraternities. Various sects and subsects have appeared and disappeared over the centuries.
Whirling dance, which is the practice of the Mevlevi sect in Turkey, is just one of the physical methods to try to reach religious ecstasy (majdhb, fana) and connection with Allah. Rifgites, also called the howling dervishes, cut themselves with knives, handle red-hot iron and eat hot coals or live serpents, depending on the subsect. Other groups include the Bektashis, connected to the janissaries, and Senussi, who are rather orthodox in their beliefs. Other fraternities and subgroups chant verses of Koran, play drums or dance vigorously in groups, all according to their specific traditions. Some practise quiet meditation, as is the case with most of the Sufi orders in South Asia, a lot of them owing allegiance or being influenced by the Chishti order. Each fraternity uses its own garb and methods of acceptance and initiation, some of them which may be rather severe.
Whirling dervish dances have also become a tourist attraction, partiularly in Turkey, home of the Mevlevi order, and some are organized solely for that purpose.
Historical and political use
Note that various historical western writers have sometimes used the term dervish rather loosely, linking it to, among other things, Mahdist uprising in Sudan and other rebellions against colonial powers.