This was a sophisticated mercantile economy in which paper money was supplied by private enterprise and credit was based on the sale of contracts for the future supply of salt to the government – a commodity for which demand was exceptionally stable.

In the eleventh century, once again convinced that: she could use her great strength to usher in an era of peace, China turned to diplomacy and did so brilliantly. She discovered that it cost far less to pacify her enemies with tribute than it did to maintain an elephantine army, so she paid her enemies off. To keep these hulking powers from her th

in 1689 at Nerchinsk in south-eastern Siberia K’ang-hsi surrounded the Russian negotiators with a large army and forced them to renounce the whole vast area north of Manchuria – a defeat for Russian expansion that was not reversed until 1860.