The Nine Armies' War: the first great war of the Bangkok era

Why Burma invaded

King Bodawpaya came to the throne in 1782, the same year King Rama I founded Bangkok. He had consolidated his power in Burma and had just conquered Arakan, and he meant to do what King Hsinbyushin had done 18 years earlier: take the Siamese capital, at a time when the new capital was not yet firmly established.

In earlier wars the Burmese had come by two or three routes and joined forces in front of the capital. This time Bodawpaya enlarged the old plan: his armies were to come in through every pass at once, so that Siam would have to divide its men until too few were left to hold the capital.

Nine armies, five directions

The 1st army went furthest south, against the southern towns on both coasts. The 2nd attacked Ratchaburi and Phetchaburi. The 3rd came down from Chiang Saen, and the 9th came in by way of Tak. The 4th to 8th armies, 89,000 men in all, more than half of the whole force and led by King Bodawpaya in person, came through Three Pagodas Pass and headed straight for Bangkok. The table below sums up all nine.

How Siam deployed its armies

When prisoners taken by a Mon scouting party in November 1785 revealed the invasion, King Rama I called a council of princes and ministers. The decision was not to split the army to meet every column, but to meet the most dangerous one first. The largest force, 30,000 men under the Front Palace prince, went to face the Burmese main force at Lat Ya. Another 15,000 took up position at Nakhon Sawan, 5,000 held Ratchaburi, and the royal army of 20,000 stayed in Bangkok as a reserve.

The southern towns and Thalang got no help from Bangkok at first, because they were far away and the enemy there did not threaten the capital directly. Only after the victory on the Kanchanaburi front were the same troops moved south. This was Siam's key principle throughout the war: to use a small force on one front at a time instead of spreading it across every front at once.

Timeline

Dates on this page are in the Common Era. Thai sources date the war in the Buddhist Era, and old documents began the new year around April, so they count the events of January to March 1786 (BE 2329) as still falling in BE 2328. That is why many Thai books place the whole Nine Armies' War in BE 2328 (1785).

• July 1785: the Burmese 1st army takes up position at Mergui and begins to stockpile supplies.
• November 1785: a Mon scouting party captures Burmese soldiers, and Siam learns that a great invasion is coming.
• December 1785: the Front Palace prince marches to Lat Ya. The Burmese vanguard attacks the Mon detachment at Kram Chang Pass. In the north the Burmese begin the siege of Lampang; in the south Chumphon and Chaiya are burned.
• January 1786: King Rama I leads the royal army to Lat Ya, then returns once he sees that the Burmese are close to breaking.
• 17 February 1786: the Siamese storm the Burmese camps at Lat Ya. King Bodawpaya orders the royal army to withdraw.
• Late February 1786: the vanguard of the 2nd army is broken at Khao Ngu, Ratchaburi.
• Early March 1786: the Front Palace prince takes a fleet to the south.
• 13 March 1786: the Burmese fleet withdraws from Thalang.
• 18 March 1786: the Burmese camp at Pak Phing is stormed. The 9th army withdraws from Tak.
• Late March 1786: the Siamese army reaches Lampang. The Burmese lift the siege and fall back to Chiang Saen.
• March–April 1786: the Front Palace prince's army breaks the Burmese at Chaiya and recovers Nakhon Si Thammarat. The Nine Armies' War is over.
• February 1787: the Tha Din Daeng campaign. Burma comes again, by one route only, and is beaten in three days.

Why the larger army lost

The first reason is supplies. An army of 144,000 has to eat every day, but most of the routes it used ran through forested hills with no towns. Food had to be carried from Burmese territory, and the further the army advanced, the longer the supply line grew. Siam therefore did not need to break the great army in battle: by cutting its supply lines and playing for time, it let the Burmese weaken on their own. The Burmese chronicle itself records that soldiers went so hungry they dug up taro and yams and ate their pack animals.

The second is coordination. The nine armies were hundreds of kilometres apart and had no way of getting news of one another in time. The 2nd army was still advancing on Ratchaburi after the royal army had already withdrawn. The 9th sat waiting for the 3rd, which was stuck at Lampang. A plan that looked frightening on paper turned into nine small wars that did not help one another.

The third is that Siam changed the way it fought. Instead of defending from behind the city walls and waiting for the floods, as before, it marched out to meet the enemy at the frontier, chose its own battlefields, and moved the same troops from one front to the next. Commanders such as the Front Palace prince, Phraya Kalahom Ratchasena and Phraya Cha Saenyakon fought from Lat Ya to Khao Ngu and on to Chaiya within two months.

After the war

Those who had served well were rewarded. Prince Anurak Thewet was raised to the Rear Palace. Khun Ying Chan and Khun Muk of Thalang became Thao Thep Krasattri and Thao Si Sunthon. Phra Maha Chuai of Phatthalung became Phraya Thukkharat. The commanders who had been careless at Ratchaburi were removed from their posts.

Burma came again the following year, in the Tha Din Daeng campaign, and was beaten even faster. After that it never again sent a large army in from the west. Later wars moved to Lanna, while Siam went on the attack against Tavoy. The Nine Armies' War was thus the turning point that made Bangkok secure as the capital.

Who was who in the Nine Armies' War

• King Rama I (Phra Phutthayotfa Chulalok): planned the defence, held the royal army in reserve, and went north in person to support the fighting at Pak Phing.
• Prince Maha Sura Singhanat, the Front Palace prince: King Rama I's younger brother. He commanded at Lat Ya, then went on to Ratchaburi and the south. The Burmese called him Phraya Suea, “the Tiger Lord”.
• Prince Anurak Thewet: a nephew of the king, the son of King Rama I's elder sister. He commanded in the north and after the war became the Rear Palace prince.
• King Bodawpaya: the Burmese king of the Konbaung dynasty, who planned the nine armies and led the royal army himself.
• Phraya Kalahom Ratchasena and Phraya Cha Saenyakon: the Front Palace prince's vanguard commanders, who stormed the camps at Khao Ngu and at Chaiya.
• Prince Khun Nen: the leader of the guerrilla force that cut the Burmese supply line behind the Lat Ya front.
• Phraya Maha Yotha (Cheng): the Mon commander who held the delaying position at Kram Chang Pass; the ancestor of the Khotchaseni family.
• Chao Kawila: the ruler of Lampang, who held his town against the 3rd army for three months.
• Khun Ying Chan and Khun Muk: the leaders of the people of Thalang in the defence of their town, later Thao Thep Krasattri and Thao Si Sunthon.
• Phra Maha Chuai: the monk who led the people of Phatthalung in building a camp against the Burmese, later Phraya Thukkharat.