China is regarded as a country with a cohesive and continuous "4000 years" of history. Yet "China" has historically been divided into separate states, had vastly borders that drastically shrunk and expanded, and in many respects doesn't seem all that different from European history--states merge, fall, rise, etc. See this gif. Hence the opening line of Romance of the Three Kingdoms: “The Empire, long divided, must unite: long united, must divide.”
When did this concept of China as a singular, cohesive, and enduring political/cultural unit emerge? Once it did emerge, was it enduring, or something that was periodically abandoned/readopted by successive Chinese states for political reasons?
The Zhou dynasty is the first historically referenced Chinese imperial dynasty where an Emperor, King of Kings, ruled over a group of Kings, who generally each controlled a city state. The executive was termed a King as well, the King of Zhou, but the other states still had their own names such as Yan, Yin, Han, Jin, Wei, Qi, and Qin. The last of these, the western kingdom of the Qin dyansty, established an equestrian monarchy called the Qin. He took the name of a mythical chinese deity, the Yellow Emperor, and said he inherited it from the last King of Zhou. His name was Qin Shi Huang Di, whose tomb contains thousands of terracotta life size soldiers, a moat of pure mercury believed to have related to his attempts to achieve immorality, and massive intricate jade sculptures dating to the time of his death, even including jade soldiers. Much of the tomb remains unexcavated due to fears of disturbing numerous artifacts.
There's been a ton of threads about this before. Here's one:
TLDR: depends on what you mean by 'singular, cohesive, and enduring political/cultural unit'
There definitely has been some sense of cultural uniformity and centrality since pre-unification times. e.g. the aristocracy of the various Warring States, even long after nominal vassal allegiance to the Zhou state had become irrelevant, shared certain cultural norms which were thought to set the central kingdoms apart from barbarian polities on the periphery. But the specific connotations of the word 中国 have evolved quite a bit over time.
Zhou dynasty (about 1000BC) pioneered the concept of Son of Heaven. Basically, the King of Zhou was considered a ruler sent by heaven to rule all man-kind. All other kings, chiefs were considered King of Zhou's subjects and must obtained permission to rule their kingdom. It is sometime describe as the tributary system by historian. 800 years later, the Qin dynasty took one step further, the Qin king defected all other Chinese kingdoms and proclaimed himself as the Emperor of China. He converted the previous kingdoms as provinces of China and unified a common written language.
Since then almost all Chinese kingdoms/empires don't recognize other kingdoms as their equal. If two dynasties exist at the same time, they must either go to war with each other or one must pay tribute to another one and recognize the other as the real Son of heaven.
Believe it or not, this concept is still there today. The People's Republic of China and The Republic of China (Taiwan) don't recognize each other as legitimate ruler of China, at least on paper.
