In around third century BCE, An Dương Vương established the capital of Âu Lạc in north of present-day Hanoi, where a fortified citadel is constructed, known to history as Cổ Loa, the first political center of the Vietnamese civilization pre-Sinitic era, with an outer embankment covering 600 hectares. In 179 BC, the Âu Lạc Kingdom was annexed by Nanyue, which ushered in more than a millennium of Chinese domination. Zhao Tuo subsequently incorporated the regions into his Nanyue domain, but left the indigenous chiefs in control of the population. For the first time, the region formed part of a polity headed by a Chinese ruler.