Welcome to the perplexing and bungled study of ethnicity in China, clouded by so many levels of nationalistic and modern biases, imprecise methods of ethnography in ancient Chinese historical sources and speculation. It will get even worse when you move past the Jin dynasty...
Ethnicity in ancient China is very confusing. There are tons of vague points, and things are complicated even further by the fact that many important ethnic groups have assimilated to the point of becoming Chinese. I think in many ways it is often irrelevant. If the Zhou were of different stock than the Shang, it ultimately isn't as important as the fact that the Zhou inherited a certain cultural tradition from the Shang, to varying degrees. Culture was very important in identification in ancient China, possibly moreso than ethnicity. If people became Confucians (or sometimes Daoists, Buddhists), learned to converse in Chinese and adopted Chinese customs, they could "become Chinese." The opposite was true too as many Chinese could defect to the northern frontier, adopting the customs, habits and lifestyles of non-Chinese (and some did). I think Nicola di Cosmo offered a very interesting interpretation of the kingdoms of Chu and Qin in Ancient China and its Enemies: The Rise of Nomadic Power in East Asian History. He mentions that even states recognized as Chinese, such as Chu and Qin, were at times labeled under the Zhou as "Yi-Ti" (something along the lines of "barbarians"). In his opinion, this classification sometimes just meant that these states labeled "yi ti" were disloyal the Zhou order in one way or another. It didn't necessarily have the ethnic connotation that might be apparent.
I'm not sure that this is the right answer though. Ethnicity is just too confusing a subject. I don't think China was the center of a single civilization or group of people. There were many groups of people and civilizations that developed concurrently with one another and interacted with each other. China is such a large country (even in ancient times) that it's very feasible to me that the people of kingdoms on the periphery (i.e. Qin/Zhou) were of different ethnicity than their contemporaries, but merged with them over time.
Of course, the ethnicity or identity of ancient people such as Zhou and Shang peopl are not specifically told. Therefore, the best way to determine their ethnicity is through archaeology evidence. The oracle bones script from Shang and bronze inscriptions from Zhang have writings believed to be the ancestors of modern day Chinese characters.
http://en.wikipedia....cle_bone_scripthttp://en.wikipedia....ze_inscriptionsEven if the identity Han Chinese only created during the Han dynasty, judging from those archaeology evidence, it is safe to say that Shang and Zhou people are the same ethnic, the ancestors of Han Chinese, that including the ruler of Zhou and Shang.
If there is any state considered foreign such as Chu, it is not in the sense of ethnicity, but it because they have different politic point of view and not entirely loyal to the Zhou as suggested by Nicola di Cosmo. The situation is similar to modern day China and Taiwan. Both of them are majority Han Chinese ethnic, but Taiwanese view China as foreign and don't consider themselves as part of China. Hope that make sense.
If Mongol have Genghis Khan to unite many of the nomadic tribes of northeast Asia and create Mongol empire, then Han Chinese have Qin Shi Huang who unified all those different civilization but share similar ethnic background. That is why Qin Shih Huang conquest is considered unification.
Regarding the origin of ruler of Zhou, I'm not sure about his origin. Do you guys have any sources regarding Zhou rulers background? Anyone can post a map of Hua civilization and how far it extent? I thought Shanxi is geographically almost the same as Shang dynasty and Zhou state was located in Wei River, somewhere around yellow river and the area where Sino-Tibetan(Han Chinese) originated from.
The Zhou state was located in the Wei River valley in present day Shaanxi Province.
http://en.wikipedia...._Zhou#Biography
http://en.wikipedia.org/wiki/Wei_River
Edited by Rykard, 14 August 2011 - 04:24 AM.