Rong 戎 was an old general term for nomadic tribes of the northwestern territories, or the western tribes of the "four barbarians", roaming the area of modern Shaanxi, Gansu, Ningxia. The other "barbarians" were the Yi 夷 (east), Hu 胡 (north), and Man 蠻 (south). The Rong were therefore also known as the Western Rong 西戎.
During the Spring and Autumn period 春秋 (770-5th cent. BCE) the mightiest tribes of the Rong were Yun Rong 允戎, Jiang Rong 姜戎 (identical to the Qiang 羌?), and Quan Rong 犬戎. Chinese scholars think that the Yun Rong were descendants of the Xuanyuan 玁狁 (also written 獫狁) that had at the end of the Western Zhou period 西周 (11th cent.-770 BCE) conquered the capital of the Zhou empire, Zongzhou 宗周 near modern Xi'an 西安, Shaanxi. They caused the flight of the Zhou dynasty to the east, and thereby incuded the Eastern Zhou period 東周 (770-221 BC) during which the royal house was critically weakened against the feudal lords. Traditionally the oldest known people of the northwest, the Hunyu 葷鬻 (also written Xunyu 獯鬻, Xunyu 薰育 or Hunyun 葷允) are said to be ancestors of the Rong.
The Yun Rong lived in the regions of modern Shaanxi, Ningxia and Gansu and regularly plundered Chinese border villages. King Xuan of the Zhou was the first to undertake a military expedition to pacify the belligerent Rong tribes. In the early Spring and Autumn period a lot of Rong and Di 狄 people migrated to the east and came as far as Weirui 渭汭 and Huanyuan 轘轅 (modern Yanshi 偃師, Henan), and also moved into the Han River 漢水 valley. Their ethnical identity is unclear.
Jiang Rong are identified with the Qiang, a Tangut people. The Quan "Dog" Rong are seen as the descendants of the Quan Yi 畎夷 of the Shang period 商 (17th-11th cent. BCE). Ancient histories say that the Quan Yi migrated into the region of Bin 邠 and Qi 岐 in the early decades of the Shang period. During his phantastic travel to the West, King Mu of Zhou 周穆王 (10th cent. BCE) met the Quan Yi and moved them to the region of Taiyuan 太原, modern Shanxi. They proved to be an unruly people, and King Yi of Zhou 周夷王 (r. 894-879) had to undertake a military campaign to pacify them.
King Li 周厲王 (r. 878-841) and King Xuan 周宣王 (r. 827-782) likewise fought against the Rong tribes, with changing success. King Xuan, for instance, defeated the Tiao Rong 條戎 and the Ben Rong 奔戎. During the reign of King You 周幽王 (r. 781-770) the royal father-in-law, Marquis Shen 申侯, even joined an alliance with the Western Rong and the Lord of Zeng 繒. Their troops attacked the royal army and defeated it in the battle of Mt. Lishan 驪山, where the king died fighting. His successor, King Ping 周平王 (r. 770-720 BCE) moved the capital to Luoyi 雒邑 (modern Luoyang 洛陽, Henan) in the east, in order to escape the permanent attacks of the Rong.
The consequence of this eastward movement was that the region of the west was in the hands of the various Rong tribes. The lords of Qin 秦 who remained there as vassals of the Zhou, had to cope with the martial Rong and the Qin therefore also became a militarily experienced people. The lord of Qin was therefore ennobled and became the first feudal lord in his dynasty. He is known as Duke Xiang of Qin 秦襄公. The dukes of Qin were able to submit a lot of Rong tribes, like the Mianzhu 綿諸, Hun Rong 緄戎, and Diyuan Rong 翟獂戎, as well as the Yiqu Rong 義渠戎, Dali Rong 大荔戎, Wushi Rong 烏氏戎 and Quyan Rong 朐衍戎.
Yet Rong tribes continued expanding to the east. The Luhun Rong 陸渾戎, Yangju Rong 揚拒戎, Quangao Rong 泉皋戎 and Yiluo Rong 伊洛戎 even lived not far from the new royal capital Luoyang and even sometimes dared to attack the royal seat. Rong people even advanced as far as the kingdom of Chu 楚 in the far south. The Rong tribes living the north of the states Zhao 趙 and Yan 燕 were called Shan Rong 山戎 "Mountain Rong". The various Rong tribes vanished during the Warring States period 戰國 (5th cent.-221 BCE) and merged with the Chinese population.
The belligerent character of the Rong resulted in the use of the word rong 戎 as a general term for "war".