Being aware of its weakness, Song dynasty decided to make an alliance with Ching (Jin) dynasty (1122-1234) of northern Manchuria. However, the alliance was not stable and soon they turned on the Song forcing them to retreat and establish a new capital in the South in 1135. Therefore, the Southern Song (1127-1279) relates to the period after the dynasty lost control of northern China to the Ching Dynasty (Ebrey, 1999).
The Song dynasty exceeded their predecessors in the development of economy. The economy of the Song Dynasty was among the most flourishing and advanced economies in the world at that time. One of the most distinct features of Song economy was large investments in joint stock companies and in multiple sailing vessels. Highly intensive overseas trade along the Grand Canal and Yangzi River brought huge monetary gain on such investments (Ebrey, 2006, p.157). Private businesses occupied those industries that were not owned by the government and both private and government-owned industries satisfied the needs of increasing Chinese population during the Song rule. During the rule of this dynasty China became the first state in the world history that issued paper money. Although the Song dynasty left the inner China, the southern territories still controlled by them contained more than half of the overall population of the country as well as the most fertile agricultural land (Ebrey, 2006, p.167).
Social organization during the Song rule was rather complex and several largest cities in the world (over one million) emerged in China during this era. The government carried out numerous social welfare programs such as establishment and support of retirement homes, public hospitals, and graveyards for the poorest. Education was also highly developed at that time (Ebrey, 1999, p. 167).
In an attempt to increase its military potential, the Southern Song Dynasty reinforced its naval power to protect its waters and land borders and developed innovative military technology based on the use of gunpowder (Ebrey, 1999). Peaceful technologies also flourished during the Song era. Thus, many remarkable improvements to mathematics, cartography, and navigation methods were made during this period. The pound lock for the Chinese system of canals was invented in the 10th century. The device represented a notable achievement in terms of hydraulic engineering: it allowed to regulate water levels for different segments of a canal to facilitate and improve safety and capacity of traffic through it (Needham, 1986, pp.350-351).
New architectural methods and techniques were developed during the Song rule. Throughout the 10th and 11th century a series of books were written describing such aspects of architecture as structural engineering, design and specific technical tricks (e.g. slanting struts built into pagoda towers for diagonal wind bracing) (Needham, 1986, p.141). Besides, the Song era was characterized by increasing interest to history and arts. Impressive collections of contemporary arts as well as ancient relics became a distinct feature of the Song period (Ebrey, 1999).
The Song dynasty supported intensive foreign relations with its neighbors, namely India, Egypt, Indonesia, and Central Asian states that were the largest China's trade partners. However, the relations with China's closest