At the beginning of the 1240s a new state appeared on the territory between the River Irtysh and the Danube. These vast lands, stretching from central Europe as far as Central Siberia, had been conquered by the Mongols, and were ruled by the Mongol Jujid dynasty (named after the eldest son of Genghis Khan, Juji). This new state came to be known in Russian chronicles as the Golden Horde. The Jujid state embraced within a single system two types of economy: the nomadic economy of the steppes and an urban economy. In the 15th century it split into separate khanates.