Jiuzhen (Vietnamese: Cá»Âu Chân, Chinese: ä¹ÂçÂÂ) was a Chinese commandery within Jiaozhou. It is located in present-day Thanh Hóa Province, Vietnam.
Michel Ferlus (2012) and Frédéric Pain (2020) propose that ä¹Âç Old Chinese *kuÃÂ-cin transcribed *k.cin, a local autonym which is reflected in Puoc ksiÃÂà  muÃÂl & Thavung ktiÃÂà Âò meaning "human being, people". Both ksiÃÂà  and ktiÃÂà Âò are from Proto-Vietic *kciÃÂà Â, which consists of prefix *k- and root *ciò (âÂÂleg, footâÂÂ); thus, "human beings" are "(those who are) on foot", "those who stand on their feet."
Pain further suggests that "Cá»Âu Chân might therefore have been inhabited by some ancestors of the Southern Vietic Thavung - Aheu."
In 111 BC, Jiuzhen was formed after the Han conquest of Nanyue.
In 157, Chu ÃÂạt rebelled in Jiuzhen and was defeated.
In 377, Li Xun seized Jiuzhen.