Mongol Military Campaign Against the Kingdom of Đại Việt (1257-1258): Tactics of the Parties, Organization of Troops, and Features of Battles

Abstract

The purpose of the research paper is to analyze the Mongol military invasion of the kingdom of Đại Việt in 1257-1258, to examine the tactics and strategies of the warring parties, the features of that campaign, and the reasons for its failure.

The scientific novelty. Based on the analysis of contemporary narrative sources and works of historians, it has been found out that the military campaign endured for approximately one month, several battles took place, the population put up fierce resistance, resorting to active ‘guerrilla tactics’, and the campaign’s defeat was attributable to a confluence of factors. The battle near Dong Bo Dau, which, according to Vietnamese historians, took place on January 29, 1258, and became one of the decisive battles in that campaign, is analyzed in detail.

Conclusions. The Mongol invasion of Đại Việt in 1257-1258 was aimed at subjugating and plundering the kingdom, turning it into a vassal state, and establishing a springboard for an attack on the Southern Song. Aggression followed a typical pattern, including ultimatums to the ruler of Đại Việt, preparation, and invasion. The Mongol army, bolstered by detachments from the subjugated kingdom of Dali, found itself outnumbered by the Vietnamese forces (approximately 30 thousand fighters against 60 thousand), but it had advantages in cavalry, tactics, and, most importantly, significant combat experience.

The invaders broke into the Đại Việt territory in December and on January 17, 1258, defeated the Vietnamese troops in the battle near Bình Lệ Nguyên and captured the capital, Thang Long, but were unable to capture/liquidate the emperor, did not completely vanquish the Vietnamese army, and faced fierce resistance from the population, food shortages, and tropical diseases. The population of Đại Việt demonstrated unity in their struggle against the aggressor; the Vietnamese army and population waged a ‘guerrilla war’ against which the Mongols could not take effective countermeasures.

Without a fleet, the Mongols could not cross rivers, transport food, military equipment, and reserves, and therefore could not conduct long-term offensive operations. At the end of January 1258, the Mongols were compelled to end their military campaign and retreat from the kingdom’s territory, losing at least half their troops.

The Mongol military campaign against Đại Việt in 1257-1258 was unsuccessful. Concurrently, the warfare demonstrated that the light infantry and war elephants of Đại Việt were incapable of withstanding the enemy, who had formidable cavalry and a substantial number of archers. Having failed in 1257-1258, the Mongols did not abandon their plans to conquer Đại Việt, repeating their attempts in 1284-1285 and 1287-1288.