upper class. Despite their small numbers, the Hoa were disproportionately dominant in the Vietnamese economy having started an estimated 70 to 80 per cent of pre-fall of Saigon's privately owned and operated businesses. Communist intervention was then deemed necessary by wide swathes of the Vietnamese population and the Soviet Union and is considered to be an ingrained symbol of the Vietnamese identity by some. Many Hoa had their businesses and property confiscated by the Communists after 1975, and many fled the country as boat people due to persecution by the newly established Communist government. Hoa persecution intensified in the late 1970s, which was one of the underlying reasons for the Sino-Vietnamese War. The Vietnamese government's post-1988 shift to economic liberalization has revived the entrepreneurial presence of the predominantly urban Chinese minority allowing them reassert some of their previous economic clout in the Vietnamese economy, despite no longer dominate the economy because of the fierce competition with the Kinh Vietnamese. Contemporary Hoa economic clout however pales in comparison to the old days, where Vietnam has mostly diversified its economy, allowing global corporations to operate within Vietnam. Migration history Early history According to folklore, prior to Chinese domination of northern and north-central Vietnam, the region was ruled by a series of kingdoms called Văn Lang with a hierarchical government, headed by Lạc kings (Hùng kings), who were served by Lạc hầu and Lạc tướng. In approximately 257 BCE, Văn Lang was purportedly annexed by the Âu Việt state of Nam Cương. These Âu Việt people inhabited the southern part of the Zuo River, the drainage basin of the You River and the upstream areas of the Lô, Gâm, and Cầu Rivers, according to Đào Duy Anh. The leader of the Âu Việt, Thục Phán, overthrew the last Hùng kings, and unified the two kingdoms, establishing the Âu Lạc polity and proclaiming himself King An Dương (An Dương Vương). In 179 BC, the Âu Lạc Kingdom was annexed by Nanyue, which ushered in more than a millennium of Chinese domination. Zhao Tuo incorporated the regions into Nanyue but left the indigenous chiefs in control of the population. This was the first time the region formed part of a polity headed by a Chinese ruler, Zhao Tuo posted two legates to supervise the Âu Lạc lords, one in the Red River Delta, named Giao Chỉ, and one in the Mã and Cả River, named