Uzbekistan, officially Republic of Uzbekistan, Uzbek Ŭzbekiston or Ŭzbekistan Respublikasi, country in Central Asia. It lies mainly between two major rivers, the Syr Darya (ancient Jaxartes River) to the northeast and the Amu Darya (ancient Oxus River) to the southwest, though they only partly form its boundaries. Uzbekistan is bordered by Kazakhstan to the northwest and north, Kyrgyzstan and Tajikistan to the east and southeast, Afghanistan to the south, and Turkmenistan to the southwest. The autonomous republic of Qoraqalpoghiston (Karakalpakstan) is located in the western third of the country. The Soviet government established the Uzbek Soviet Socialist Republic as a constituent (union) republic of the U.S.S.R. in 1924. Uzbekistan declared its independence from the Soviet Union on August 31, 1991. The capital is Tashkent (Toshkent).