The Tang Dynasty fell around 907, when there were incursions from invaders from the north. These invaders took over a great deal of land in the northern and western parts of China, and there was a period of chaos in China. In 960, the Song Dynasty was founded. During the Northern Song Dynasty (960-1127), the Song defeated the Liao Empire in the northeast with the help of the Jurchens, a northern nomadic tribe with a strong military. The Jurchens then turned against the Song and captured their capital, Kaifeng. The Jurchens made Kaifeng their own capital and established the Jin empire. Only the southern part of the Song Empire remained within Chinese control. 

The Jurchens were warlike people who prized horses, hunting, and archery, but, after settling in China, they turned to urban and less warlike modes of life and intermarried with other groups in China. They assimilated into Chinese culture and, although they originally had a shamanistic religion, began to practice a form of Confucianism. At first, Jurchen conquerors ordered Han Chinese to shave the front of their heads and wear their type of clothing, but these restrictions lessened over time. The Jurchens were eventually conquered by the Mongols in 1234.

The major impact of the northern nomads on China during this time was that the threat of the nomads led to discontent within China.  This happened because of the expenditures needed to deal with the nomads.

Particularly during the Song dynasty, China was paying tribute to northern nomads.  At the same time, it was having to maintain large armies to try to protect itself.  Both of these things took a lot of money.  To raise the money, the Chinese government had to increase taxes.  This stressed the Chinese population and helped to lead to discontent among peasants and others who were burdened by the taxes.