Orenburg (əryĭnbōrkˈ) [key], formerly Chkalov chkäˈləf, city (1989 pop. 547,000), capital of Orenburg region, Central Asian Russia, on the Ural River. It is a major rail junction where the Trans-Caspian RR, the Central Asian RR, and the Samara-Orenburg line meet. Other industries produce agricultural machines and machine tools, elevator equipment, leather goods, clothing, foods, and silk. Founded in 1735 as a fortress, Orenburg resisted (1773–74) a siege by Pugachev. It became a center for Russian trade with Kazakhstan and central Asia. It was called Chkalov from 1938 to 1957.