Wendi built the Grand canal, which connected the Huang He and the Chang Jiang. As a coin has two sides, the Grand canal also had it own advantages and disadvantages. It provided a vital route for trade between the northern cities and the southern cities. In addition, it also made the transportation between north and south more quickly and efficiently. For example, it helped transports the rice grew in south where had more warm climate and was more suitable for farming to north where lacked the food. However, a million peasant men and women toiled five years to dig the more than 1000-mile waterway and many people died. The increasing discontent caused people revolt at the end