Harlequin (or Arlecchino in Italian, Arlequin in French, and Arlequín in Spanish) is the most popularly known of the zanni or comic servant characters from the Italian Commedia dell'arte and its descendant, the Harlequinade. The Harlequin is also known to be a type of clown.
Idries Shah has claimed that the name Harlequin is of Sufi origins  Classical sufi masters were indeed known to wear a pieced robe made of a patchwork of coloured fabric as early as the 11th century AD. Shah argues that the Arabic name aghlaq - which was given to such sufi masters - with plural form "aghlaqueen" pronounced with the guttural gh- as the Spanish jota, would have given the word Harlequin.
For others the origins of the name remain uncertain. One of the origins postulated for the modern Harlequin is Hellequin, a stock character in French passion plays. Hellequin, a black-faced emissary of the devil, is said to have roamed the countryside with a group of demons chasing the damned souls of evil people to Hell. The physical appearance of Hellequin offers an explanation for the traditional colours of Harlequin's mask (red and black).
Popular theories suggest that the character, and possibly the name, may have come from France, Africa, or Italy. Others attribute the name to Dante's Inferno, XXI, XXII and XXIII; one of the devils in Hell having the name Alichino. Although illustrations of Arlecchino have only been dated as far back as 1572, the character had existed before this date.
The Harlequin character may have been based on or influenced by the Zanni archetype who, although a slow thinker, was acrobatic and nimble. Interpreted thus, Harlequin's distinctive motley costume may be a stylized variant of Zanni's plain white garb, designed to reflect the ad-hoc patching necessary to prevent the garment's degradation.
Zan Ganassa, whose troupe is first mentioned in Mantua in the late 1560s, was one of the earliest known actors believed to have performed the part. Another early Italian exponent of the role was the Bolognese actor, Nicolò Zecca, active c. 1630 in Bologna as well as Turin and Mantua. Ganassa had performed in Paris in 1571 and 1572, and further transformations of the character occurred in France, where Arlecchino was performed at the Comédie-Italienne in Italian by Tristano Martinelli, Giovan Battista Andreini, and Angelo Costantini (c. 1654–1729). The role was played in French as Arlequin in the 1660s by Dominique Biancolelli(it), who combined the zanni types, "making his Arlecchino witty, neat, and fluent in a croaking voice, which became as traditional as the squawk of Punch." The Italians were expelled from France in 1697 for satirizing King Louis XIV's second wife, Madame de Maintenon, but returned in 1716 (after his death), when Tommaso Antonio Vicentini ("Thomassin", 1682–1739) became famous in the part.
Characteristics and dramatic function 
The primary aspect of Arlecchino was his physical agility. While generally depicted as stupid and gluttonous, he was very nimble and performed the sort of acrobatics the audience expected to see. The character would never perform a simple action when the addition of a cartwheel, somersault, or flip would spice up the movement.
Within these restrictions the character was tremendously elastic. Various troupes and actors would alter his behaviour to suit style, personal preferences, or even the particular scenario being performed. He is typically cast as the servant of an innamorato or vecchio much to the detriment of the plans of his master. Arlecchino often had a love interest in the person of Colombina, or in older plays any of the Soubrette roles, and his lust for her was only superseded by his desire for food and fear of his master. Occasionally, Arlecchino would pursue the innamorata, though rarely with success, as in the Recueil Fossard of the 16th century where he is shown trying to woo Donna Lucia for himself by masquerading as a foreign nobleman. He also is known to try to win any given lady for himself if he chances upon anyone else trying to woo her, by interrupting or ridiculing the new competitor.
He eventually became something more of a romantic hero around the 18th century, when his popularity provoked the Harlequinade.
Duchartre lists the following as variations on the Harlequin role:
Trivelino or Trivelin. Name is said to mean "Tatterdemalion." One of the oldest versions of Harlequin, dating to the 15th century. Costume almost identical to Harlequin's, but had a variation of the 17th century where the triangular patches were replaced with moons, stars, circles and triangles. In 18th century France, Trivelino was a distinct character from Harlequin. They appeared together in a number of comedies by Pierre de Marivaux including L'Île des esclaves.
Truffa, Truffaldin or Truffaldino. Popular characters with Gozzi and Goldoni, but said to be best when used for improvisations. By the 18th century was a Bergamask caricature.
Guazetto. Costume like the old Zanni's but accessorized with a sort of poncho, or otherwise a giant three-tiered collar. Known for his dancing.
Zaccagnino. Character dating to the 15th century.
Bagatino. A juggler.
See also 
- Idries Shah Los Sufis Editorial Kairós, 2007 p.433
- Gerstle Recovering the Orient: Artists, Scholars, Appropriations Routeledge 1995 p.80 
- Grantham, B., Playing Commedia, A Training Guide to Commedia Techniques, (Nick Hern Books) London, 2000
- Jean-Claude Schmitt (1999). Ghosts in the Middle Ages: The Living and the Dead in Medieval Society. University Of Chicago Press. ISBN 978-0-226-73888-8.
- "Online Etymology Dictionary". Etymonline.com. Retrieved 2012-01-03.
- "harlequin - Definitions from Dictionary.com". Dictionary.reference.com. Retrieved 2012-01-03.
- Rudlin, J., Commedia dell’Arte, An actor’s handbook, Routledge, London, 1994
- Laurence Senelick in Banham 1995, "Ganassa" p. 409.
- Boni, Filippo de' (1852). Biografia degli artisti ovvero dizionario della vita e delle opere dei pittori, degli scultori, degli intagliatori, dei tipografi e dei musici di ogni nazione che fiorirono da'tempi più remoti sino á nostri giorni. Seconda Edizione. Venice; Googlebooks: Presso Andrea Santini e Figlio. p. p. 1103.
- Senelick in Banham 1995, "Harlequin" p. 472.
- Donald Roy in Banham 1995, "Comédie-Italienne" pp. 233–234.
- Senelick in Banham 1995, "Vicentini" p. 867.
- Banham, Martin, editor (1995). The Cambridge Guide to the Theatre (new edition). Cambridge: Cambridge University Press. ISBN 978-0-521-43437-9.
- Oxford Dictionaries article on Harlequin
- The dictionary definition of harlequin at Wiktionary
- Media related to Harlequin at Wikimedia Commons
- Chisholm, Hugh, ed. (1911). "Harlequin". Encyclopædia Britannica (11th ed.). Cambridge University Press.