Dancing that involves moving the hips and stomach. Serious performers of the sophisticated genuine article began to refer to it as "Middle Eastern Dance" in the 1980s. Strictly speaking, what Westerners think of as belly dancing is the Arabic raqs sharqi style. Some historians believe it was a way of exercising the muscles of the pelvis and abdominal area for women who were pregnant or had menstruation problems; or that it was part of a religious ceremony. Nowadays it's more for entertainment purposes (with titilation of their loved one being the reason some women pick it up even today), although it can be utilized as a form of exercise too. The style has spread from Egypt and Turkey to Western countries.
The revealing outfits are a more recent addition to the dance; female dancers of the original raqs sharqi style dressed more conservatively. To set the table here, we really need to note that what the West knows as belly dancing is something of an artificial construction. As noted above, it's generally "raqs sharqi" (Oriental Dance), which is a more sexualized version of the traditional dance of the Arab World, developed for the entertainment of wealthy men, and thus only practiced by women. However, the traditional dance of several countries is similar; this is particularly true of the Egyptian raqs balady ("native/local dance"), which is practiced by both men and women and shares many moves with the other thing. So in other words, if you ever see a guy on the dancefloor who looks like he's bellydancing: (1) well, he is, but (2) he's probably just Egyptian.
Unlike strippers or burlesque dancers, many professional belly dancers are hired to perform in the presence of mixed audiences (men, women and children). Throughout its traditional Middle Eastern homeland and increasingly elsewhere, it is not uncommon to see belly dancers, male or female, performing at weddings, baby showers, bridal showers, or even retirement parties. Children will often learn to belly dance at a young age as well. Perhaps unsurprisingly given the similarities to if not roots in Egyptian folk dance, Egypt is the home of modern belly-dancing. The Egyptian film industry in particular is probably responsible for the spread of the style within the Arab World—from the earliest days of Egyptian film up until about the 1970s, most Egyptian movies had a belly dance scene (often shoehorned in to feature a famous or promising dancer, much like a Bollywood Item number), and many Egyptian filmmakers still like to drop a dance into a movie at the slightest provocation. Egypt has thus produced the following famous names in the art, generally making their names in film:
One of the earliest big film dancers was Taheyya Kariokka
, the founder of modern raqs sharqi. Coming into the industry in the 1930s-40s, she took her stage name from the fact that she had learned some Brazilian Samba moves and incorporated them into her style (carioca being the Brazilian Portuguese term for a person from Rio de Janeiro). The samba influence she brought into the dance can still be seen in today's dance if you know what you’re looking at. (See what we mean about it being a construction?) Later, Fifi Abdou codified many of the norms of the art. She eventually shifted into ordinary acting. To this day, her name is synonymous with everything sexual in Egypt (she is long since retired).
Western dancers blended raqs sharqi (often called "cabaret" in the West) with hip-hop and ballet to create "Tribal Fusion" bellydance, as demonstrated by Edenia Archuleta.
In Turkey, it is not uncommon for a slender, veiled dancer to perform a belly dance on the more sensual end of the scale, and then unveil to reveal that it was a male dancer, to the consternation (and in some cases probably delight) of the spectators. Obviously, the regular version exists there as well.
China has undergone a popularity boom in terms of belly dancers, from many professional dancers emerging from the country to countless new students wishing to learn. This new fad is believed to be the work of former singer Wen Kexin, who fell in love with belly dance after having to learn it for a music video she took part in. Supposedly, China now has at least 100 schools dedicated to belly dance, all led by former students of Wen Kexin.
Mata Hari's style of dance was not strictly bellydance (more like "exotic dance" inspired by belly dance), but her revealing outfits and alluring persona are generally accepted to be a significant influence on the genre and its perception, at least in the West.
