Tobolsk was founded by Yermak's Cossacks in 1585-86 during the first Russian advance into Siberia near the ruins of Siberia Khanate's capital Qashliq. It became the seat of the Viceroy of Siberia and prospered on the trade with China and Bukhara. It was there that the first school, theatre, and newspaper in Siberia were established. Daniel Defoe made his Robinson Crusoe stay in Tobolsk from September 1703 to June 1704.Tobolsk is the only town in Siberia and one of the few in Russia which has a standing stone kremlin, or elaborate city-fortress, built at the turn of the 17th and 18th centuries. Its white walls and towers with an ensemble of churches and palatial buildings spectacularly sited on a high river bank were proclaimed a national historical and architectural treasure in 1870.