Throughout what Europe often terms the Middle Ages, China was ruled by several dynasties, all of which experienced their own periods of expansion and prosperity followed by decline and demise. The three most important were the T'ang, the Song, and the Ming. The T'ang was the earliest. Building upon the stability instilled by their Sui ancestors, the T'ang emperors expanded China's influence both politically and economically. They were toppled only after internal strife and rebellion made them susceptible to foreign invasion. The Song reestablished central authority a half-century later. Though they were less powerful than the T'ang, Song emperors were great patrons of the arts, and many of the artistic techniques and cultural styles we associate as 'Chinese' today began in this period. Nearly a century after the Song fell to Mongol invasion, the Ming took control of China and built upon the successes of the Song to create an efficient and meritocratic central bureaucracy, which helped the Ming maintain stability and expand China's territory and influence. However, the Ming also eventually fell to foreign invasion in 1644.
Humans have occupied Japan for tens of thousands of years, but Japan’s recorded history begins only in the 1st century BCE, with mention in Chinese sources. Contact with China and Korea in the early centuries CE brought profound changes to Japan, including the Chinese writing system, Buddhism, and many artistic forms from the continent. The first steps at political unification of the country occurred in the late 4th and early 5th centuries CE under the Yamato court. A great civilization then developed first at Nara in the 8th century and then at Heian-kyō (now Kyōto) from the late 8th to the late 12th century. The seven centuries thereafter were a period of domination by military rulers culminating in near isolation from the outside world from the early 17th to the mid-19th century. The reopening of the country ushered in contact with the West and a time of unprecedented change. Japan sought to become a modern industrialized nation and pursued the acquisition of a large overseas empire, initially in Korea and China. By late 1941 this latter policy caused direct confrontation with the United States and its allies and to defeat in World War II (1939–45). Since the war, however, Japan’s spectacular economic growth—one of the greatest of any nation in that period—brought the country to the forefront of the world economy. It now is one of the world’s foremost manufacturing countries and traders of goods and is a global financial leader.
Historian Michael Wood has created a wonderful documentary called "The Story of China."
It is available to watch on YouTube and Amazon.
To discover more go to this website: https://www.pbs.org/story-china/home/
Crash Course Video of Chinese History
Here is a quick overview of Japanese History from Bill Wurtz
An Animated History of Japan