Wen. Thus the Sui Dynasty was founded, with Chang'an the capital and Luoyang the auxiliary capital. In 589, the Sui Court defeated the last of the Southern Dynasties, Chen, and unified the whole nation. As a result of the reunification, the society became stable and peaceful which encouraged economic and political development. At the beginning, the agricultural acreage increased greatly which promoted the crop yield. The skills industry made some new advances with the shipbuilding technology reaching a new high level. Meanwhile, the commerce in Luoyang was fairly prosperous and in order to develop the national economy, a series of policies,such as Juntian System and Zutiao System, was carried out. This equally distributed the farmlandand moderated the tax rates while increasing the fiscal revenue. In order to enhance the communication between southern and northern areas, Emperor Yang ordered his people to dredge a grand canal running from north and south. Centering on Luoyang, the Grand Canal was more than 2.5 miles long and functioned as the main artery in the Nation's transportation. The Grand Canal played an important role in economic and cultural exchange between southern and northern areas. There were also many changes in political life. A new political system - Three Departments and Six Ministries was established - the first in Chinese history. Under this system, the royal power was enhanced and the work division in the court became detailed. Since this dynasty, the method of selecting talent was thoroughly overhauled.