The 735-737 Japanese smallpox epidemic caused between 1.5 to 2 million deaths, accounting for about one-third of the Japanese population. The epidemic originated in Kyushu and later spread to the capital of Heicheng. By 737, the epidemic caused the suspension of government affairs and the death of four Fujiwara brothers who controlled the government at the time. The epidemic has had a profound impact on Japan's society, economy and religion.