Expansion across the Urals into Siberia and Central Asia, the largest demographic vacuum on the globe, was launched at the end of the sixteenth century; the conquest of lands in the west and north-west possessed by Sweden and Poland began in the mid-seventeenth. The pace of expansion was relentless. Between 1683 and 1914 it averaged 53 square miles per day, and may be characterized as a case of bulimia politica.
