The early history of Siberia was greatly influenced by the sophisticated nomadic civilizations of the Scythians (Pazyryk) on the west of the Ural Mountains and Xiongnu (Noin-Ula) on the east of the Urals, both flourishing before the common era. The steppes of Siberia were occupied by a succession of nomadic peoples, including the Khitan people,[citation needed] various Turkic peoples, and the Mongol Empire. In the Late Middle Ages, Tibetan Buddhism spread into the areas south of Lake Baikal.
During the Russian Empire, Siberia was chiefly developed as an agricultural province. The government also used it as a place of exile, sending Avvakum, Dostoevsky, and the Decemberists, among others, to work camps in the region. During the 19th century, the Trans-Siberian Railway was constructed, supporting industrialization. This was also aided by discovery and exploitation of vast reserves of Siberian mineral resources.