In reconstructing the early history of the Co Loa site and its surrounding area, there are three principal sources of information, namely Vietnamese oral histories, Chinese textual accounts, and the archaeological record. Until recently, historians have relied mainly on folklore and historical descriptions to reconstruct the early Iron Age of Vietnam. However, a major problem with this approach is that sources offer conflicting accounts of the Bac Bo region’s cultural and historical development. Traditional views on the origins of Vietnamese civilization were based on a combination of archaeological work done during the French colonial period and imperial Chinese historical records.
According to textual accounts, the Han Empire began colonizing the Bac Bo region at approximately 111 BC. Not surprisingly, Han texts maintain that agricultural, metallurgical, and political sophistication emerged among the local “barbarians” in Bac Bo mainly because of imperial annexation. Viewed from the Han capital, the Dongson people were the most distant of several groups known as the southern barbarians.
These Sino-centric views stand in contrast with Vietnamese oral traditions that indicate considerable complexity and centralization in the Bac Bo region well before Chinese arrival. Oral traditions hold that Bac Bo was the nucleus of an indigenously developed Vietnamese civilization with powerful kingdoms ruling over vast populations before the arrival of the Chinese. In particular, Vietnamese chronicles describe an indigenous Au Lac polity centered at Co Loa during the third century BC. In approximately 258 BC, a man named An Duong Vuong (also known as Thuc Phan) purportedly overthrew the Van Lang polity, consolidating power over the local communities with the establishment of the Au Lac Kingdom. Our knowledge of this kingdom is a mixture of legend and history. Choosing Co Loa as his capital, he proceeded to construct a fortified citadel known to history as Co Loa Thanh, thus named because its walls were laid out in concentric rings reminiscent of a snail shell. According to these accounts, by the third century BC, Co Loa already possessed the various fortifications still visible today.
Given the hazy and sometimes conflicting nature of oral and textual accounts, the archaeological record is vital for furthering our understanding of Co Loa’s history and cultural development.