What is the origin of the name "Nguyen"?
I supposed the name "Nguyen" mentioned in the question is the surname Nguyen, the most popular Vietnamese surname. This answer is based on that assumption. I would be thankful of suggestions for improvement.
It is an indisputable fact (so obviously) that the Vietnamese surname Nguyen (Nguyễn), was of Chinese origin (the surname itself, not its bearers). Many answers traced the origin of this surname back to Chinese surname 阮 (ruǎn in Mandarin or yun˩ in Cantonese - for convenience's sake I use "Ruan" as the Chinese equivalence of Nguyen, although it is obvious that the surname's pronunciation in Ancient Chinese would be greatly different from that), but saying that Nguyen was originated from Ruan is not sufficiently precise. The Vietnamse surname Nguyen and the Chinese surname Ruan are essentially cognates of one surname . The origin of the Vietnamese surname Nguyen therefore the same with that of the Chinese surname Ruan, and there is no way but to trace the surname's meaning back to China.
1. The earliest sources mentioned Ruan as a place name. Ruan was a small state in Ancient China during the Shang Dynasty, Its location was in the of modern day Jingchuan County of Pingliang City, Gansu Province (in Vietnamese: huyện Kính Xuyên, thành phố Bình Lương, tỉnh Cam Túc). Geographically, it means that Ruan lay by the farthest west of the Shang empire, and was probably no more than a distant vassal. That was a small city-state, around 30 km north-south and 20 km east-west; the capital Gong 共 was located in the centre. The state was conquered by King Wen of Zhou (it was before the fall of the Shang Dynasty) in 1054 BC (sorry Ruans, you couldn't even make it to the Spring and Autumn period). I am eager to explain more about the geography and history of the state of Ruan; however that is not the point of this answer. In this map you can find the names of Ruan 阮 and Gong 共 near the western frontier of Shang China.
The surname Ruan no doubt originated from the name of this state: many inhabitant of the conquered Ruan state fled eastward to Shang's capital of Zhaoge, and adopted Ruan as their surname. That area corresponded to Western Han's Chenliu commandery 陳留郡 (which was murch larger than the modern day Chenliu town, and covered large areas on both banks of the Yellow River, including both modern day Zhaoge in the north and Kaifeng in the south. That explains the common saying that the surname Ruan originated from the Chenliu commandery.
2. There is a family of Chinese lutes called ruan. Originally called Qin pipa, it was later named after Ruan Xian, a scholar, musician and a skilled player of that instrument, who lived during around the 3rd century AD. It was believed that Ruan Xian greatly innovated the instrument as well as its performing style. The named Ruan Xian lute (Ruanxianqin) was later shortened to "ruan".
Beside being the surname, that musical-related meaning of 阮 is probably the most well-known meaning currently in use of this character. It is also likely the meaning most people give when asked about the meaning of 阮. However, it is not the original meaning of the character. There are many Chinese surnames that were named after objects, trades, professions, etc, but it is also obvious that the lute Ruan was name after the surname Ruan and not the vice versa. As this meaning was derived from the artist's surname, it thus could be traced back to the original meaning (point 1 above).
My hypothesis on the origin of the surname Nguyen/Ruan/阮
It is a consensus, and I have also noted above, that Ruan was the namesake of a place name, an ancient state in China. Using place names as surnames is a common phenomenon in both the East and the West. There rises another question: But why then was that very place got the name "Ruan" from the start? There has been no consensus about that. We all know Anatole France's surname was after the country of France, which in turn originate from the kingdom of the Franks people. These Franks themselves were thus called because they are free people and " franc " meant " free " in their language - at least that is the most agreed hypothesis. We also know that the "Viet" in the name of "Vietnam" is a cognate of Chinese 越 (Mandarin: yuè) which means "pass over/beyond/more" which was used to name the Yue peoples who lived in extreme remoteness from the Central Plains. What I mean is whether we can do similar tracing with the surname Nguyen?
Personally, I favour one explanation which, although not being original research, should however be taken with cynicism: The element 元 is not purely phonetic as it might seem. During the earliest stage of the Chinese language (as well as other language), it is a common phenomenon for the same sound to be expanded to signify a concept that share similarities with the original concept. As a result, during that earliest stage, it is probable that a phonetic relationship between words also implies a semantic relationship somehow, and not a pure coincident, as with the homophones.
Taking into account that:
- The state of Ruan existed and was destroyed during the Shang Dynasty (it was destroy by King Wen of Zhou), when the Chinese writing system was only at its foundation stage, and when the language's lexicon was basic and was on its expansion. The name of the state would definitely be very ancient and probably even predated the invention of the writing system in China.
- 阮 and 元 were both very antique characters. Many of the oldest Chinese characters from this period are pictograms and ideographics, and although the development of phono-semantic characters like 阮 was also on the way, these early photo-semantic characters mostly reflected derivative words already in existence before the development of writing, rather than new, invented words. That is exactly true for the name of the state of Ruan, which came into existence even before the foundation of the Shang dynasty.
These two facts help to consolidate the hypothesis about the semantic aspect of the seemingly phonetic element 元 in the character 阮: Originally, the primitive, pre-written, sound of 阮 and 元 are polysemes (one sound with different, related meanings) rather than homophones . Along with the development of the Chinese writing system, that same sound was assigned different characters to signify the different semantic aspect to be expressed.
What semantical element can be extracted from the element 元 if I count on that phono-semantic relationship hypothesis? The primitive 元 (in oracle bone script) was the drawing of a man with a big, emphasised head, and meant " head ".
元's derived meanings include: the source / the origin / the first . Does that imply the meaning of Ruan as a place name? Does Ruan mean: "head land", the "source land", or "the origin land"? There are some facts to support that:
- The state of Ruan was located by the upper Jing River , closer to the sources than other city-states (the state of Zhou, on the other hand, was located much further downstream, where the Jing River flows into the Wei River). That can explain the "source land" meaning.
- According to legends, a descendant of Gao Yao was enfeoffed by Shang the land upstream the Jing river, and they established the state of Ruan. As the Shang was centred around the Middle Yellow River, the foundation the Ruan settlement must be a later westward expansion upstream.
- Moreover, as the state of Ruan lay at the very western fringe of the Shang empire, and there was no other state more upstream than Ruan, can the name be used to indicate that fact?
While I claim that 阮and 元 are polysemes . (with identical sound), however, their pronunciations are considerably different in Modern Mandarin: ruǎn for 阮 and yuán for 元. In order to verify the claim, we have to trace back the pronunciations of those two characters in Old Chinese. It turns out that although ruǎn and yuán sounds quite distinct in modern Mandarin, it is almost similar in many southern Chinese languages (including Sino-Vietnamese), and were pronounced identically in Old Chinese ( when the state of Ruan was founded.
According to Baxter-Sagart's reconstruction of Old Chinese, 元 was pronounced as /ŋon/, which is very close to Vietnames "nguồn" /ŋuɜn/ which was borrowed from an early period, probably from Old Chinese. The more recently adopted Sino-Vietnamese pronunciation of 元 "nguyên" /ŋwiɜn/ was actually closer to its Middle Chinese pronunciation /ngjwon/. Another loanword "ngàn" (mountainous hinterland) was a later alternative pronunciation of "nguồn".
While Baxter-Sagart didn't provide the Old Chinese pronunciation for 阮, Zhengzhang provided /ŋonʔ/, which is exactly the same with 元, with a final glottal stop. Moreover, in Hakka, considered by many people the oldest Chinese language and can be traced back to Old Chinese (other Chinese languages are traced to Middle Chinese), 阮 is pronounced /ŋon/ with a rising tone. On the other hand, we should also bear in mind that tones in Chinese were developed much later, and that Old Chinese had no tone. As in Middle Chinese, the rising tone in Hakka is usually a relic of an ancient final glottal stop in Old Chinese. If that is the case, 阮 would sound like /ŋonʔ/ in Old Chinese.
Moreover, the development of the final glottal stop itself occurred in a much latter period after the state of Ruan was found and destroyed, I can safely assume that it was not there when the state was named. Last but not least, as the presence or absence of the final glottal stop affects the succeeding sound rather than the sound itself (which makes sense since 阮 was intended to be a proper noun and a place name), we can conclude that 阮 /ŋonʔ/ and 元 /ŋon/ had identical pronunciation in Old Chinese.
The origin of the surname Nguyen (and the Chinese character that is associated with it) can be summarised in the following steps:
In Old Chinese (or should I say Proto-Chinese?), the sound /ŋon/ meant "head". There had been no writing system yet.
The word’s meaning was later expanded to included derived meanings "source", "origin".
A city-state was named /ŋon/ meaning "head/source/origin", because it was found on the source of the river Jing.
Chinese primitive writing system was later invented: head /ŋon/ was written as 元 - of course they used Oracle Bone script which might looks