Kiev (or Kyiv), Ukraine's capital and largest city, is located in the north-central part of the country on the Dnieper River. It is Ukraine's leading centre for industry, commerce, science and education. The city grew enormously between 1950 and 1980. A powerful technological complex with dozens of industrial companies was created, employing many highly skilled personnel. Kiev also became an important military centre for the Soviet Union. Because these developments created a large demand for labour, migration increased from rural areas in both Ukraine and Russia.