Petropavlovsk, city, northern Kazakhstan. It lies along the Esil (Ishim) River in the centre of the Esil Steppe. Petropavlovsk was founded as a Russian fort in 1752 and soon became an important centre of trade between Russia and Central Asia and the Kazakh steppes. The Trans-Siberian Railroad reached Petropavlovsk in 1896, and by 1917 the population was nearly 50,000. Petropavlovsk now has some notable industrial undertakings and is also important as the junction of the Trans-Siberian and Trans-Kazakhstan railroads. The city has a theatre, a television station, and a teacher-training institute. Pop. (2006 est.) 190,092.