Bashkortostan or Bashkiria, officially the Republic of Bashkortostan, is a republic of Russia between the Volga river and the Ural Mountains in Eastern Europe. The republic borders Perm Krai to the north, Sverdlovsk Oblast to the northeast, Chelyabinsk Oblast to the east, Orenburg Oblast to the south, Tatarstan to the west and Udmurtia to the northwest. It covers 143,600 square kilometres and has a population of 4 million.