Rulers of the Northern Song Dynasty adopted the policy of “internal defense and external slackening”. On the one hand, they did their best to strengthen the centralized autocracy. The bureaucracy became more and more inflated and redundant, which caused the treasury to become more and more depleted. On the other hand, they weakened the defensive power of the Northern Song Regime when confronted with military threat from the outside and took an appeasement and passive policy by presenting an annual gift of silver and silk in exchange for temporary tranquility on the northern border, which consumed great amount of national power, and deteriorated the situation. Later the State of Jin grew stronger in the north conquering the Northern Song Regime. The remnant forces of the Song Dynasty fled south. The continuation of the Northern Song regime in the south of China is known to historians as the Southern Song. Up to the 13th century, the Mongols vanquished the regimes of Xia, Jin and Southern Song. Kublai Khan founded the Yuan Dynasty and united China.
The flourish of culture under the rule of the Northern Song Regime made a striking contrast with its humble and weak external image. The cultural representative of this period was Li Xue, a Confucian school of idealist philosophy, also known as Neo-Confucianism or Cheng-Zhu Li Xue School of Confucianism. This new school, which was developed by combining Confucianism with Buddhism and Taoism, was pioneered by Cheng Hao, Cheng Yi in the Northern Song Dynasty and Zhu Xi in the Southern Song Dynasty — the founders of Cheng-Zhu Li Xue School of Confucianism. This school was the consummate ideological system in Chinese feudal society and raised the level of ancient traditional thought to the crowning phase of development. This ethics encouraged the cultivation of the scholars’ morality and loyalty to the sovereign and to the country. However, it also suppressed human nature.
Unlike the energetic and daring martial spirit in the Han-Tang Dynasties, the prevailing social practice of this period was characterized by the trend in scholar-officials to pursue elegant and good taste, resulting in the weakening and refining of personality. This was an outcome of the combination of the orders of the day: laying stress on the cultural achievement while making light of the military exploits. Along with the development of urban economy, the urban culture gradually became popular. The scroll of painting entitled The Festival of Pure Brightness on the River presented a vivid panorama of the town life then. Song ci and Yuan opera represented the zenith of the literature during this period. Besides, this period was another important period of the merging of nationalities in Chinese history. Despite the confrontation between the Northern Song and Xia and Liao and the rivaling regimes of Southern Song and Jin, economic and cultural exchanges between the Han nationality and the nationalities of Dangxiang, Qidan and Nüzhen ended up with an integration between them. In the Yuan Dynasty, the unprecedentedly vast domain and easy communications enhanced contacts home and abroad. The formation of Hui nationality was in fact a fruit of ethnic merging.
During the Song period, science and technology were highly developed. The Chinese further developed the art of printing, the making of the gunpowder and compass — three great inventions of China as great contributions to the world. Bi Sheng invented the movable-type printing. The technique of block printing reached its stage of maturity. Gunpowder was used in war and the proportion of different elements in the composition of gunpowder was close to that of today. The compass was employed in navigation in the Northern Song Dynasty. Shen Kuo, the great scientist of the Northern Song Dynasty wrote Sketchbook of Dream Brook — an indication of the splendid achievements made by the Song in natural science. This scientific encyclopedia covered astronomy, mathematics, physics, chemistry, biology, geography, meteorology, medicine, and engineering technique.