The first settlement was in 1718, when the Russians built a fort beside the river Irtysh, near a ruined Buddhist monastery. The monastery's seven buildings lent the fort (and later the city) the name Semipalatinsk (Russian for Seven-Chambered City). The fort suffered frequently from flooding caused by the snowmelt swelling the Irtysh, and in 1778 the fort was relocated 18 km upstream to less flood-prone ground. The small city grew around the fort, largely servicing the river trade between the nomadic peoples of Central Asia and the growing Russian Empire. The construction of the Turkestan-Siberia Railway added to the city's importance, making it a major point of transit between Central Asia and Siberia.
Between 1917 and 1920, it was the capital of the largely unrecognized Alash Autonomy, a state formed during the Russian Civil War. The city was called Alash-qala during the Alash Autonomy years. It was recaptured by Red Army forces loyal to Petrograd in 1920.
In 1949, a site on the steppe 150 km (93 mi) west of the city was chosen by the Soviet atomic bomb programmed to be the location for its weapons testing. For decades, Kurchatov (the secret city at the heart of the test range named for Igor Kurchatov, father of the soviet atomic bomb) was home to many of the brightest stars of Soviet weapons science. The Soviet Union operated the Semipalatinsk Test Site (STS) from the first explosion in 1949 until 1989; 456 nuclear tests, including 340 underground and 116 atmospheric tests, were conducted there.
Semey has suffered serious environmental and health effects from the time of its atomic prosperity: nuclear fallout from the atmospheric tests and uncontrolled exposure of the workers, most of whom lived in the city, have given Semey and neighboring villages high rates of cancer, childhood leukemia, impotence and birth defects.
Modern Semey is a bustling university town with a population exceeding 300,000. Its proximity to the border, and the