Great changes in political structure and social and economic life define the Sui, Tang and Song dynasties. Each period laid the foundation for the next, with changes and improvements to create a new order. The Sui Dynasty reigned from 581 to 618 AD. The emperor built monasteries for both Buddhism and Taoism throughout the country and appointed Buddhist monks as his chief advisors. (Duiker, & Spielvogel, 2009) The Han examination system based on the Confucian classics was revived. Taxation was reformed and a census was introduced to create fair tax collection. Additionally, each taxable male was given a grant of land. Once a male reached the age of 60, a portion of the land was returned to the government, the rest could be passed on to his heirs. (Halsall, 1998) This was also a period of great construction. During the Sui, the Great Wall was rebuilt and the Grand Canal was built. Connecting the Huang, Huai, and Yangtze Rivers, the Grand Canal has had a huge impact on travel, commerce, and socializing in China. The Tang Dynasty was founded in 618 and lasted until 907. The emperor was supreme and government officials were chosen by examination. A census was carried out to simplify tax collection and to recruit citizens to work for the empire. This was a period of great territorial expansion. (Halsall, 1998) The emperor also had a great love for the arts, and the Tang period became known as the golden age of literature and art. Block printing was invented and made writing more available. (Unknown, 2003) Shipbuilding and firearms development were also perfected during the era. The art was heavily influenced by Buddhism, particularly rock sculpture. One of the main problems that arose was the heavy tax burden. Many were unable to cope with the heavy tax burden. To escape this, many placed themselves under the protection of large landowners who were exempt from taxes, or became bandits. (Halsall, 1998) The Song dynasty is actually divided into two separate periods: the Northern Song from 960 to 1126 AD and the Southern Song from 1126 to 1279 AD. The northwestern part of the country had been conquered by nomadic tribes, forcing The emperor moved the capital to Kaifeng, then to Hangzhou during the Southern Song period. They also lost control of Tibet. (Duiker, & Spielvogel, 2009) While struggling for control of territory, the Song fought for economic development and cultural success.