Early in the 22nd Buddhist century, Ayutthaya fought continuously with Hongsawadee after Pra Chairaja’s reign. The first war, which started in 1538, was caused by an attempt to claim unoccupied territory around Chiang Kran. The area was owned by the Mons who refused to be under Burmese Hongsawadee’s power. Tabeng-Shweti, King of Taungoo, sought help from Ayutthaya. The conflict and war between the two empires, then, developed. The war ended with the victory of Ayutthaya, due to the ability and strength of the King and his military force.
Another war occurred during the reign of King Mahathammaraja in 1548 C.E.. There were political changes at the time: deaths of Pra Chairaja and Pra Yodfa, and the power of Taw Srisudajun who later was overthrown by Pra Tianraja. He established himself as a king called Pra Mahajakrapat. King Tabeng-Shweti perceived the instability as an opportunity to expand his territory to the Ayutthaya Kingdom. He arranged a large army and moved it to the edge of Ayutthaya. The war began. Ayutthaya was at a disadvantage due to the smaller size of their forces and lack of political stability within King Mahajakrapat’s new administration. Pra Chairaja, the King’s former rival who overthrew Taw Srisudajun, brought down his army from Pitsanulok to accompany the King’s troops. The Hongsawadee army was banished from Ayutthaya.
From the two wars, it is clear that the Ayutthaya Kingdom was able to maintain its independence despite its internal conflicts. Its administrative power remained strong, and the control of its forces was effective. In the first war, Ayutthaya conquered Hongsawadee because King Chairaja was a skilled and strong commander. Although during the second war, Ayutthaya was at a disadvantage and Pra Siriyothai was killed, close ties between the kingdom and northern provinces brought about help and victory to Ayutthaya. Those ties were strengthened by intermarriage between dynasties.
Over a period of time, Hongsawadee was still determined to expand its power over Ayutthaya. King Mahajakrapat possessed seven white elephants. The Hongsawadee Kingdom under King Burengnong, a new king with a genius for war planning, requested that Siam give him the white elephants as a tribute to good relations. King Mahajakrapat could not follow the request. King Burengnong took that as reason to declare war.
Because King Burengnong had been part of the army in the previous war, he realized that the northern provinces could bring their forces down to encircle the Burmese force. In this war in 1473, Burma attacked those northern provinces including first weakening their militaries. Ayutthaya experienced great difficulty and ended up losing some of its white elephants to Hongsawadee.
The Siamese kingdom was not devastated by the war. King Mahindarathirat, the new king of Ayutthaya at the time, was committed to working towards regain independence for the kingdom. He believed that Ayutthaya should not tolerate Hongsawadee’s control and betrayal of the leader of Pitsanulok. He began to build up alliances to counter Burma. He sent Pra Tepkasatri to Lanchang to enhance the relationship between Ayutthaya and Lanchang. Pra Mahathammaraja, ruler of the city of Pitsanulok was informed about this and took her to Hongsawadee. The incident made King Mahindarathirat so angry that he declared a war between Ayutthaya and Pitsanulok.
Hongsawadee considered Ayutthaya’s declaring war with Pitsanulok as inappropriate, as the province was under supervision of Hongsawadee. King Burengnong, consequently, moved his army to Ayutthaya. Ayutthaya lost its independence.
In 1568, the Hongsawadee army was close to Ayutthaya and the battle began. The capital was the base to defend the Kingdom. Ayutthaya royal annals indicated that Hongsawadee failed to conquer Ayutthaya despite several attacks. Different tactics were used by Burma to defeat Ayutthaya. The actual turning point of the war happened when King Mahindarathirat sent messages requesting help from Prachao Chaiyachetthatirat of Lanchang to move his troops, who later encircled the Burmese forces. Although Prachao Chaiyachetthatirat was aware of what had been happening in Ayutthaya and sent the force to help Ayutthaya, King Burengnong army figured out the plan and arranged a force to secretly attack the Lanchang army at Ban Maksongton, Saraburi District. The Lanchang force was destroyed. King Mahindarathirat could not count on the help from Lanchang anymore, as demonstrated in 1548 when Pra Mahathammaraja’s troop from Pitsanulok could not make it to Ayutthaya. The only hope for the Kingdom was water from the North that would flood the Burmese camp.
This war proved that good relations between Ayutthaya and nearby provinces were very crucial to support the stability of the central city. Once an opponent removed support from those provinces, the center would be isolated and easily defeated.