Was the Ben Hai river in Vietnam a pre-colonial dividing line?

Hi

I haven’t been able to establish whether the Ben Hai river in Vietnam was a pre-colonial dividing line that separated northern Vietnam from southern Vietnam during the dynastic struggles in ancient/pre-French colonial Vietnam or was it first established by the Geneva Conference resolution of 1954.I have a feeling that it predates the Geneva resolution.
I look forward to your feedback.

Didn’t it separate Vietnam from the Champa states until Vietnam took them over?

I was thinking more in term of the Nguyen(south) and Trinh(north) wars and the border that existed between their domains. I believe that the river separated their territories but I haven’t found anything specifically stating that.

I’m pretty sure the Nguyens controlled Quang Bing, which was north of the river.

Thanks Captain America. So wouldn’t that make the Ben Hai river a natural border?Is that why the Geneva Conference settled on the Ben Hai river as the 17th Parallel? Did the Ho Chi Minh trail run through it? There must have been at least cultural reasons for choosing that river as dividing line.

I think it was largely a question of the situation on the ground. The 17th parallel and Ben Ha I were largely the border between Viet Minh and French controlled areas.

And the Ho Chi Minh trail was built by the North Vietnamese after the partition to get Viet Cong and supplies for them south into South Vietnam.

Thanks Captain America. I thought it was more than just a coincidence that that particular area was designated by the Geneva Convention as the 17th Parallel, since it was also a pre-colonial border area between the Trinh and Nguyen domains.

Well, it wasn’t exactly. The Nguyens extended north of the river.

I see. Which area exactly?

Quang Binh and Ha Tinh.

Thanks Captain Amazing. Really helpful.