Cao Lo

The old chronicles say

Three texts give three names and three crossbows. The Giao Chau ngoai vuc ky calls the maker a spirit man named Cao Thong and states the weapon's power as a figure: one shot kills three hundred men. The Viet su luoc calls him Cao Lo and describes the bow in a strikingly technical way — a lieu crossbow that looses ten shots — and says he trained ten thousand soldiers to use it. The Complete Annals use the name Cao Lo, note that some texts write Cao Thong, and have him make the weapon from the claw the golden turtle pulled off and handed to the king, called the holy crossbow of the sacred light and the golden claw.¹²³

A fourth version sits in the notes of the Cuong muc, quoted from a Chinese book: the spirit Cao Thong made An Duong Vuong a crossbow that killed ten thousand of the enemy at one shot and thirty thousand at three. That is four figures for one crossbow across four texts — three hundred men a shot, ten bolts at a time, ten thousand men a shot, and in the best-known version no figure at all, only the turtle's claw. The later the text, the less the crossbow is a weapon with specifications and the more it is a sacred object.⁴

How later ages remembered

The Complete Annals add a side story that today's telling drops almost entirely: a dream of the Tang governor Cao Vuong, whose army was passing through Vu Ninh, in which a stranger calls himself Cao Lo and says he once served An Duong Vuong and won great merit in driving off the enemy, and was then slandered by a Lac lord and had to leave. The detail matches the two earlier texts, in which the crossbow-maker also leaves the king. The line lose the able man first, lose the country after was in the story from the beginning; by the late version it has been pushed down into a side dream, and the centre given over to a love affair and a sword stroke.³¹²