(self-designation of the Blackbone Yi is Nosu; other Yi call themselves the Acheh, Ahsi, and other names), a people in southern China, living primarily in the vicinity of Liangshan in Szechwan Province. In China the Yi number 4.7 million people (1970, estimate); several thousand Yi live in the Democratic Republic of Vietnam. Their language belongs to the Tibeto-Burman branch of the Sino-Tibetan language family.

The Yi haVe preserved their ancient traditional beliefs. Their ancestors were the Ts’uan tribes (third century A.D.). In the seventh century six tribes, the Chao, formed the Nan-chao kingdom, which existed until the middle of the 13th century. During this period cultural monuments, epic literature, and a hieroglyphic writing system were created. Until the 1950’s specific systems of slaveholding, tribal organization, and castes were preserved among the Yi in the area of Liangshan. The entire Nosu caste, or the Blackbone Yi, were slaveholders; the Chiino, Achia, and Hsiahsi castes were slaves. The right to tribal organization, which protected the lives and interests of its members, was enjoyed only by the Nosu and Chiino castes. The southern, northern, and western Yi engaged primarily in hoe-using agriculture; the northern and western Yi also bred cattle.

the ruling dynasty in korea beginning in 1392 (until 1897, Yi rulers used the title of kings; from 1897 to 1910 they were called emperors). The dynasty was founded by Yi Song-gye (Taejo). Under the last rulers of the Yi dynasty, capitalist powers exerted increasing influence in the country and Korea was made a Japanese colony.