The Di (Chinese: 氐; pinyin: Dī; Wade–Giles: Ti1) were an ethnic group in ancient China. They were one of the Wu Hu (Five Barbarians) that overran northern China during the Jin Dynasty and the Sixteen Kingdoms period. Note that the character 氐 (Dī) is different from 狄 (Dí), which refers to the Northern Di, an unrelated ethnic group living in northern China during the earlier Zhou Dynasty.
The Di lived in areas of the present-day provinces of Gansu, Qinghai, Sichuan and Shaanxi. During the 4th and early 5th centuries, they established Former Qin and Later Liang states of that era's Sixteen Kingdoms. They were traditional horse animal husbandry nomads, semi-nomadic shepherds, and goatherds living on the Tibet/Sichuan frontier.
Political history 
During the Jin Dynasty, the five semi-nomadic tribes of Xiongnu, Jie, Xianbei, Di, and Qiang overran northern China. Historians call this period the Sixteen Kingdoms. During that period, Di ruled the states of Former Qin (351-394) and Later Liang (386-403).
The tribe of Di was originally from the southern part of Gansu Province. Its leader was Fu Jian, who founded the Former Qin Kingdom (351-394). He established his capital in Chang'an. He appointed Wang Meng (王猛), a Han-Chinese, to be his Prime Minister. He built a highly Sinicized administration and formed a strong Han-Chinese infantry army to accompany his Di cavalry.
In 370 AD, Fu Jian conquered the Kingdoms of Former Yan (307-370) and Former Liang (345-376). As a result, Fu Jian occupied the whole of northern China. He then embarked upon a plan to conquer southern China which was under the Eastern Jin Dynasty (317-420).
In 383 AD, Fu Jian led an army of about a million strong marching south with the intention of destroying the Eastern Jin. He met the Jin's main forces at the Fei River in Anhui. The Jin Army of only about eighty thousand strong were under the command of Xie Shi (謝石) and Xie Xuan. They camped near the river, and the battle is known as the Battle of Fei River. Fu Jian's campaign to conquer the south ended in disaster and his empire fell apart. He retreated to his capital of Changan, left his son Fu Pi (符丕) in charge of the capital, and returned to his home base in southern Gansu province to find new recruits from his own Di people. While on his way, Fu Jian was captured by the soldiers of the hostile Kingdom of Later Qin (384-417). He was later hanged by the ruler of Later Qin. His son, Fu Pi, became a new ruler of the Kingdom of Former Qin. In 394 the Kingdom of Former Qin was conquered by the Kingdom of Later Qin. The Former Qin lasted for only 44 years.
Common surnames used by the Di 
- Li (李), royal of Cheng Han
- Yang (楊), Yang Qianwan of Chouchi
- Fu (符), royal of Former Qin
- Lü (呂), noble of Former Qin, and royal of Later Liang
See also 
- List of past Chinese ethnic groups.
- Qiang people (Ch'iang people)
- Cheng Han
- Later Liang
- Former Qin
- Jin shu Xie Xuan Chuan: 晉書謝玄傳: Wen feng sheng he lei, jie yi wei wang shi [聞風聲鶴唳,皆以為王師]
- Described in the Wei Lue (a 3rd century CE Chinese text) - Section 1 (at University of Washington, United States)