The Song Dynasty was ruling China from the end of the Five Dynasties - 960AD until the start of the Yuan Dynasty 1279.
The Song Dynasty is divided into two periods known as The Northern Song and the Southern Song. During the Notherne Song the dynasty controlled most of Inner China. Southern Song refers to the time when the Song lost control of the Northern part of China to the Jin Dynasty, causing the Song Court to retreat to the South of the Yangtze River and so leaving the yellow River area, the spiritual home of the Chinese.
The Song was economucally still sound as it still controlled the majority of the people and had the best of the agricultural lands. To protect its borders the Southern Song considerably increased the Naval capability and military strength of its land forces.It was also now in a position to mount maritime missions for new lands and trade
To repel the Jin and later the Mongols the Song made some huge advancements in military weaponaryas they developed the use of Gunpowder. The Jin Dynasty was taken by the Mongols who then had an uneasy relationship with the southern Song until they were able to capture the Southern Song lands in 1279 when led by the Great khan - Kublai Khan.
During the Song they developed Gunpowder, re-vitalized the civil service with the use of an examination system that had begun under the Tang Emerors but now was ramped up so only those with skill and talent reached the top, it beacame beauraucratic elite not aristocracy based. A compass that pointed to the tue north was developed, and a postal service that could deliver letters, missives any where in the kingdom within 2 days.