The Song (pronounced Soong) dynasty ranks up there with the Tang and the Han as one of the great dynasties. Fifty years after the official end of the Tang, an imperial army re-unified China and established the Song dynasty. This was a time of remarkable advances in technology, culture, and economics but the Song, despite its political failures, generally set the stage for the rest of the imperial era. The most important development during the Song was that agricultural technology, aided by the importation of a fast-growing Vietnamese strain of rice and the invention of the printing press, developed to the point where the food-supply system was so efficient that, for the most part, there was no need to develop it further. There was enough food for everyone and the system worked so it became self-sustaining. The success meant there was no incentive to improve it so the basic system thus remained unchanged from the Song up until the twentieth century. In fact, many rice farmers in the Chinese interior and in less-developed regions of southeast Asia are, for the most part, still using the antiquated Song-era farming techniques. The efficiency of the system not only made it economically self-sustaining but also reinforced the existing social structure. Consequently, society and economics were largely static from the Song until the collapse of the dynasty structure in the twentieth century.

This is important because one of the factors behind the Industrial Revolution in Europe was that they didn't have enough people to work the fields. There was an incentive to create better technology in Europe but there was not a need in China because there was no shortage of manpower. China actually had a surplus of human labor.
While the Song was a time of great advances, politically and militarily, the Song was a failure. The northern half of China was conquered by barbarians which forced the dynasty to abandon a northern capital in the early 1100's. Then a hundred and fifty years later, the Mongols, fresh from conquering everything between Manchuria and Austria, invaded and occupied China.

While the period of Mongol rule is referred to as part of the dynasty system, it was in fact a government of occupation by outsiders. While the Mongols did use existing governmental structures for the duration of their reign, the national language was changed to Mongol and many of the officials they used were non-Chinese. Mongols, Uighurs from central Asia, some Arabs and even an Italian named Marco Polo all served as officials for the Mongol government. One of the more significant accomplishments of the Mongol tenure was the preservation of China as we know it, in that China wasn't turned into pastureland for the Mongolian ponies which was common Mongolian practice for territories they'd overtaken but had actually been advocated by some of the conquering generals.

The Yuan dynasty also featured the famous Khubilai Khan and he was responsible for, among other things, extending the Grand Canal. The Yuan period was a disaster in many ways yet the reluctance of the Mongols to hire educated Chinese for governmental posts resulted in a remarkable cultural prosperity, for example, Beijing Opera was invented during the Yuan. On the other hand, attempts to analyze the failure of the Song in keeping barbarians out of China led to the rise and dominance of Neo-Confucianism, a notoriously conservative(if not outright reactionary) brand of Confucianism that had originally developed during the Song.

The Ming rulers distinguished themselves by being fatter, lazier, crazier, and nastier than the average Imperial family. After the first Ming Emperor discovered that his prime minister was plotting against him, Not only was the prime minister beheaded but his entire family along with anyone even remotely connected with him. Eventually, about 40,000 people were executed in connection with this case alone. They were also active Neo-Confucianists. In the early 1400s, a sailor named Zheng He (with a fleet of over 300 ships) sailed as far west as Mogadishu and Jiddah, and possible to Madagascar. This is nearly 100 years before Columbus had the idea of trying to sail to Asia the long way around. They was not a repeat voyage so their journey was never followed up. Conservative scholars of the court failed to recognize the importance of their efforts which meant that for the first time in history, China was turning inwards, clinging to an erroneous interpretation of an outmoded philosophy.

One of the most positive accomplishments of the Ming was they moved the capital to Beijing, fortified the Great Wall (the massive masonry structure that you see in all the pictures and postcards is, with some recent, Communist-era repair, an all-Ming construction). They also built the Forbidden City and gave Macao to the Portuguese.