Originating in what is now southern China and northern Vietnam, the Vietnamese people pushed souwaard over two millennia to occupy the entire eastern seacoast of the Indochinese Peninsula. Ethnic Vietnamese, or Viet (known officially as kinh), live in the low lands and speak the Vietnamese language.This group dominates much of the cultural and political landscape of Vietnam. The Vietnamese government recognizes 54 ethnic groups, of which the viet is the largest, according to official Vietnamese figures (1999 census), ethnic Vietnamese account for 86% of the nation's population. The ethnic Vietnamese inhabit a little less than half of Vietnam, while the ethnic minorities inhabit the majority of Vietnam's land.the Khmer Krom are found in the delta of the Meckong River, in the south of Vietnam, where they form in many areas the majority of the rural population.They live in an area which was previously part of Cambodia and which Vietnam conquered in the 17th and 18th centuries.Official Vietnam figures put the Khmer Krom at 1.3 million people. However, estimates vary from 1.1 to 7 million The relation between China and Vietnam also declined in this period, with Vietnam along with the Soviet union against China in the China-Soviet split. tensions peaked whin Vietnam invaded Cambodia, an ally of China, to depose Pol Pot, resulting in a Chinese invasion in 1979. in 1978-1979 some 450,000 ethnic Chinese left Vietnam by boat as refugees.