Note: Do not rely on this information. It is very old.
UzbegsUzbegs, a main branch of the Turki race, dominant since the 16th century in Western Turkestan (Khiva, Bokhara, Ferghana, Afghan Turkestan), originally nomads, but now mostly settled, engaged in agriculture and trade, and much mixed with indigenous Tajik (Iranian) populations, as shown by their greatly modified Mongolic type; claim descent from Uzbeg, a renowned chief of the Golden Horde (1312-42), under whom they first made their appearance on the Caspian Sea, and thence gradually overran a great part of the Turkestan Lowlands; but many local traditions, as well as tribal names, point to an intermingling of Mongolic, Turki, and even Finish tribes, amongst whom the Turki element no doubt greatly predominated, as is evident from the universal prevalence of the Turki language (Chagatai dialect). This Turki element has been traced with much probability back to the Euz or Guz, an ancient Turki people, akin to the Uigurs, who were seated in the Tian-Shan uplands, and mentioned in the Chinese records under the corrupt name of Kiu-tze or Ku-tze some centuries before the new era. The Eux hordes had already reached the Sirdarya (Jaxartes) in the 10th century, and it was from that point that they advanced round the Aral Sea to the Caspian; the kindred Turki people of the Volga still call them Oz. Although long settled and dwelling in large cities, such as Khokand, Khiva, Bokhara, and Samarkand, the Uzbegs still preserve the original tribal groups, of which over 100 are enumerated. One of these are the Uzi, and others, such as the Manghits, Kitais, Naimans, Kipchaks, Kungrads, Kalmaks, Uigurs, Kara-Kalpaks, and Chagatais, clearly indicate a medley of Mongol and Turki tribes, so that the term Uzbeg is regarded by Vambery and others rather as a political than an ethnical designation. (Vambery, De Ujfalvy, Trotter, Burnes, Meyendorf.)
Click for more about Kalpaks