The Sui Dynasty was founded by Emperor Wendi. He unified northern and southern China. He also built the grand canal. He and Yang Di created the equal field system, which lessened the gap between the rich and the poor. This enhanced agricultural productivity and centralization of government power. Coinage was reunified and standardized. The great wall was also improved upon and expanded. Buddhism was spread around the empire, unifying varied people and cultures. Citizens were forced to work hard labor on the Grand Canal and pay hefty taxes. They rebelled and this brought end to the Sui Dynasty.
The Tang Dynasty came from the fall of the Sui. The first emperor of the Tang Dynasty was Kao-tsu. He continued many practices from the Sui Dynasty. He granted equal amounts of land to every male, in return the had to pay taxes and practice local government rule. He also created a monetary system of copper and silk ribbons. He wrote a set of laws that were to be revised every two decades. The emperor Tai-tsung shrank the government at both central and state levels. Changing the size of the government saved money for the government to save food in case of famine. Also there was money for disaster relief such as flooding for farmers. After a series of feuds withing the central government, northern invaders invaded and brought an end to the Tang Dynasty.
The Song Dynasty built a centralized government with scholars as officials. They developed cities that was for trade and commerce rather than just administrative purposes. The number of merchants grew and this cause a wealthy class to grow. Arts and culture grew during this time. Poetry flourished. Art was popular and woodblock painting was often used. Many skilled craftsmen also used porcelain. The magnetic compass was also invented in this time. Politically and militarily, the empire failed. The northern part was taken over by barbarians and then the south was taken over by the Mongols.