Sushi's origins can be traced back to the 8th century in China when fish which had been salted was wrapped in fermented rice. Known as Nare Zushi, this was a means of preserving fish: The fish was eaten and the rice was thrown away. Eventually this form of preserving fish reached Japan where they not only ate the fish but also the rice. This new dish became very popular in Japan and an important part of Japanese culture. The earliest known reference to sushi appeared early in the 8th century.