Co Loa (sometimes spelled Co-Loa) is an Iron Age (Dong Son culture) site, located about 15 kilometers north of Hanoi in the Bac Bo region of northern Vietnam. First occupied about 2000 BC, the Bac Bo region saw continuous occupation during the Phung Nguyen (~1600-1200 BC), Dong Dau (~1400-1000 BC), Go Mun (~1000-600 BC), and Dongson (~600 BC-200 AD) periods. Radiocarbon dates taken on the fortifications at Co Loa suggest it was likely built ~400-350 cal BC, and expanded in a series of stages.
Architectural remains at Co Loa include the remainders of three massive earthen rampart enclosures, with a network of river-fed moats and ditches, and artificially built mounds and towers. Remnants of all three enclosing walls still stand, in heights from 3-10 meters in height and 12-30 meters wide at the base. The interior wall is the most substantial of the fortifications, amounting to five meters high, 20-30 meters wide at the base and 6-12 meters wide at the top. The inner wall includes a number of bastians and enclosing an area of some 1.65 square kilometers. The outermost wall encloses an area of some 8 square kilometers.
Artifacts recovered from Co Loa include an enormous bronze drum, weighing 72 kilograms. Bronze drums are typical of the Dong Son culture, but this drum is by far the largest yet recovered from the region. When discovered, the drum held 200 bronze objects, including 96 plowshares, six hoes, a chisel and a collection of spearpoints, axes, daggers and arrowheads. Just outside the main entrance to the outer wall was discovered a hoard of some 10,000 bronze tanged projectile points.
Historical Records of Co Loa
Oral tradition reports that Co Loa was the capital of the Bac Bo region when it was the center of a urban or proto-urban center ruled by powerful kings. Vietnamese historical documents report that there was a kingdom called Au Lac in Bac Bo. According to the records, Au Lac and Co Loa were established during the third century BC when a man called An Duong Vuong (or Thuc Phan) overthrew the Van Lang ruling dynasty. The Van Lang were the first ruling dynasty in what is today Vietnam.
In contrast, Chinese Han Dynasty records report that the area was occupied by local barbarians when they arrived in the 1st century BC. In AD 43, say the Han accounts, the local Dong Son warrior elite were incorporated as part of the Han empire province.
Archaeological evidence suggests that Co Loa was built by local people prior to Han Dynasty control in the first century AD. Archaeologists suggest that the heavy fortifications were constructed because of political turmoil during the Warring States period of China.
Archaeological Investigations at Co Loa
Co Loa was excavated in 2004-2005 by the Vietnam Institute of Archaeology, and again in 2007-2008 by an international team led by Nam C. Kim at the University of Wisconsin at Madison, and including personnel from the University of Illinois at Chicago, the Vietnam Institute of Archaeology and the Conservation Center for the Co Loa and Hanoi Citadels.
Sources
This glossary entry is a part of the About.com guide to Dong Son Culture, and the Dictionary of Archaeology.
Higham, C. 1989. The Archaeology of Mainland Southeast Asia. Cambridge: Cambridge University Press.
Higham, Charles. 2002. Early Cultures of Mainland Southeast Asia. River Books, Bangkok.
Kim NC, Lai VT, and Hiep TH. 2010. Co Loa: an investigation of Vietnam's ancient capital. Antiquity 84(326):1011-1027.
O'Harrow, Stephen. 1979. From Co-loa to the Trung Sisters' Revolt: Vietnam as the Chinese Found It. Asian Perspectives 22(2), pp. 140-163.
Taylor, Keith. 1983. The Birth of Vietnam. University of California Press, Berkeley.
Tessitore, John. 1989. View from the East Mountain: An Examination of the Relationship between the Dong Son and Lake Tien Civilizations in the First Millennium B.C. Asian Perspectives 28(1), pp. 31-44.
Wheatley, Paul . 1983. Nagara and Commandery. University of Chicago Department of Geography Research Paper Nos. 207-08, Chicago.
Yao A. 2010. Recent Developments in the Archaeology of Southwestern China. Journal of Archaeological Research 18(3):203-239.
