Excavations uncovered several ironwood poles on Wednesday in Cao Quy rice field, Lien Khe Commune, Thuy Nguyen District of northern Hai Phong City.

Each pole was planted 2.5 meters deep, with holes at the top to assist with leverage. They have a diameter of 20-50 centimeters, placed five to seven meters apart. Some were found pointing vertically, with others angled 15-20 degrees to the west or south.

Archeologists from Vietnam Institute of Archeology used carbon dating to determine the age of the stake.

Historically called ‘Battle of Bach Dang’ after the river dividing Vietnamese forces from Yuan Dynasty Mongols on a quest to expand their rule via a fleet of ships.

Commanded by General Tran Hung Dao (1226-1300), Vietnamese soldiers submerged the wooden poles in Bach Dang River prior to the fleet’s arrival, comprising 18,000 men and 400 vessels. Hidden during high tide, the stakes trapped the invaders when the tide receded, ensuring victory for Tran Hung Dao.

The landslide victory in Bach Dang River was considered the biggest naval battle in Vietnam's history and a representative triumph in Vietnam's fights against three invasions of the Mongolian empire.

A sharpened wooden stake found in northern Hai Phong City
dated back to 1270 - 1430. Photo by VnExpress/Giang Chinh.

The poles were first discovered by Nguyen Tuan Trieu, a resident of Mai Dong Village on October 1 while tilling the soil for vegetable planting.

With his family, the farmer transported two poles to the local communal house for display.

Cao Quy rice field concealed its historic wooden artifacts.
Photo by VnExpress/Giang Chinh

After learning of Trieu’s discovery, Hai Phong Museum staff and local authorities collected samples and advice on preserving the stakes.

Nguyen Duc Hien, a local resident, said villagers have known about the stakes for many years, though no one thought they dated back to the Tran Dynasty. Most people would simply chuck them when found.

Having witnessed countless historic battles, Lien Khe Commune, formerly Truc Dong, was used as the base from where General Tran Hung Dao launched his attack on the Mongolian army.