Burmese–Siamese War (1593–1600)

Early in 1593 King Naresuan sent two different forces to the cities of Tavoy and Tenasserim. The first, under the command of Phraya Chakri troops to attack Tenasserim. The second unit, under the command of Phraya Phra Khlang, to capture Tavoy.[3] Tavoy and Tenasserim were cities in Thailand during the Sukhothai period, which the Burmese had captured. However, the Governor of Tenasserim learned of the Siamese plans and sent an urgent message to the King of Burma, Nanda Bayin, who ordered an army to oppose the Siamese.[4]

Tenasserim resisted the siege for 15 days while the siege of Tavoy lasted 20 days, before the Siamese were successful in capturing both cities. Both consented to be subject to Ayutthaya as in the past.[3][5]

After Phraya Chakri captured Tenasserim, he captured Mergui and the boats in the port, which included 3 foreign sloops and 150 other boats. He then sent Phraya Thep Archun by sea to Tavoy so as to assist Phraya Phra Khlang if the Burmese advanced that far. Phraya Chakri then marched his force to Tavoy by land, leaving a garrison of 10,000 at Tenasserim under Phraya Sri Sainarong. Simultaneously, Phraya Phra Khlang sent 100 boats and 5,000 men under Phraya Phichai Songkhram and Phraya Ram Khamhaeng to assist Phraya Chakri.[6]

The Burmese had sent 200 boats and 10,000 men under the command of Samin Ubkong and Samin Phataba. This Burmese flotilla was caught in the middle of the Siamese flotillas advancing from the north and south. Many Burmese boats were sunk, some beached their boats and fled, while the rest sailed away. Saming Ubakong was killed and 500 men were captured.[7]

In 1594, the Burmese governor of Martaban, Phraya Lao, suspected the Burmese governor of Moulmein of being in league with the Siamese. At that time, the chief of the Mon people lived in Ayutthaya. The governor of Moulmein defied Phraya Lao, and sent an urgent request to Naresuan for help. Accordingly, Naresuan sent 3,000 men under Phraya Si Salai. As a result, the small Burmese garrison at Martaban abandoned the town. The King of Burma then ordered the viceroy of Toungoo to suppress the revolt, but that force was defeated by a combined Siamese and Mon army. The Mon provinces then became subject to Siam.[8][9][10][11]

After evicting the Burmese from the Tenasserim coastal region, Naresuan took the offensive feeling that he might have an opportunity to repay the Burmese for those times in the past when they pillaged Siam. As such, in January 1595, Naresuan led an army of 120,000 men from the Siamese capital and initiated an invasion of lower Burma.[12] At Martaban, he added the Mon army as an auxiliary force. Upon reaching Pegu, Naresuan invested the city for a period of three months until he learned that the viceroys of Prome, Ava, and Toungoo were coming to the aid of the city. Give the overwhelming strength of the Burmese relief forces, Naresuan ended the siege and retreated back to Siam.[11][13][14]

Taking advantage of the political turmoil in Burma in 1597–1598, Naresuan once again decided to invade Burma. Power in Burma at that time was held by Nanda Bayin as King of the Toungoo Empire in Pegu. Among the dependent provinces in Burma, however, two powerful provinces, Toungoo and Arakan, had rebelled against Nanda Bayin and expressed an interest in allying with Naresuan. As such, Naresuan assumingly felt more confident in his battleplan as he believed that he had allied himself with the viceroys of two powerful Burmese provinces .[15][16]

As Naresuan's army prepared for their march to Pegu, however, the Viceroy of Toungoo, Minye Thihathu, had second thoughts about his alliance with Naresuan. Minye Thihathu's ambition was to independently rule Burma, but he came to the realization that the conquest of Burma by Naresuan would mean his Toungoo province would become a vassal state of Siam. As such, Minye Thihathu plotted with the Viceroy of Arakan to conquer Pegu and depose Nanda Bayin ahead of Naresuan's army. In executing his plan, Minye Thihathu first created unrest and revolt among the Mon in the Tenasserim coastal region so as to delay Naresuan's invasion force. Next, Minye Thihathu and the Viceroy of Arakan convinced Nanda Bayin to relinquish the city of Pegu and relocate to Toungoo. Nanda Bayin agreed. Before the armies of Toungoo and Arakan departed Pegu they confiscated everything of value and set the city on fire. When Naresuan arrived in Pegu, he found only an empty and burning city.[15][17]

Feeling angry and betrayed, Naresuan marched his forces to Toungoo. He knew that he would now have to defeat the Viceroy of Toungoo to claim power in Burma. Upon reaching Toungoo, Naresuan was joined by his allies including the Viceroy of Chiang Mai. Toungoo was invested, the moat was drained, and the city was assaulted. For two months, Naresuan attempted to capture Toungoo but in May 1600, he gave up the fight due in large part due to a lack of provisions and returned to Siam.[18][19][20]