The invasion initially met little resistance, as the Burmese force was too large for the small guard posts on the border.
Upon hearing of the Burmese invasion, Maha Chakkraphat mobilized his kingdom, then gathered his forces at Suphanburi, a town just west of Ayutthaya.
When Tabinshwehti and his Burmese army arrived at the walled town of Kanchanaburi, they found it deserted.
The King of Burma then continued his march eastward, capturing the villages of Ban Thuan, Kaphan Tru and Chorakhe Sam Phan.
Tabinshwehti divided his army into three columns, the first commanded by Bayinnaung, the second by the Viceroy of Prome, and the third by Yong, the Governor of Bassein.
The Burmese continued their advance and captured the ancient town of Uthong as well as the villages of Don Rakhang and Nong Sarai and closed on Suphanburi.
When the Burmese attacked the town, the Siamese defenders could not withstand the onslaught and retreated towards Ayutthaya.
Tabinshwehti ordered his army southeast along two canals, and crossed the Chao Phraya River near Phong Phaeng.
From here he encamped his army directly north of the Siamese capital of Ayutthaya on a field called the Lumpli Plain.

Maha Chakkraphat left the capital with his forces to engage Tabinshwehti and test Burmese strength.
On this occasion, he mounted his chief war elephant.
Accompanying him were his Chief Queen, Sri Suriyothai, and one of their young daughters, Princess Boromdhilok, the two riding together on a smaller war elephant.
Both royal ladies were dressed in male military attire (helmet and armour), with the queen wearing the uniform of an Uparaja.
Also accompanying their father on elephant mounts were two sons, the Uparaja and heir apparent, Prince Ramesuan, and his brother Prince Mahin.
The invasion initially met little resistance, as the Burmese force was too large for the small guard posts on the border. Upon hearing of the Burmese invasion, Maha Chakkraphat mobilized his kingdom, then gathered his forces at Suphanburi, a town just west of Ayutthaya. When Tabinshwehti and his Burmese army arrived at the walled town of Kanchanaburi, they found it deserted. The King of Burma then continued his march eastward, capturing the villages of Ban Thuan, Kaphan Tru and Chorakhe Sam Phan. Tabinshwehti divided his army into three columns, the first commanded by Bayinnaung, the second by the Viceroy of Prome, and the third by Yong, the Governor of Bassein. The Burmese continued their advance and captured the ancient town of Uthong as well as the villages of Don Rakhang and Nong Sarai and closed on Suphanburi. When the Burmese attacked the town, the Siamese defenders could not withstand the onslaught and retreated towards Ayutthaya. Tabinshwehti ordered his army southeast along two canals, and crossed the Chao Phraya River near Phong Phaeng. From here he encamped his army directly north of the Siamese capital of Ayutthaya on a field called the Lumpli Plain.
Maha Chakkraphat left the capital with his forces to engage Tabinshwehti and test Burmese strength. On this occasion, he mounted his chief war elephant. Accompanying him were his Chief Queen, Sri Suriyothai, and one of their young daughters, Princess Boromdhilok, the two riding together on a smaller war elephant. Both royal ladies were dressed in male military attire (helmet and armour), with the queen wearing the uniform of an Uparaja. Also accompanying their father on elephant mounts were two sons, the Uparaja and heir apparent, Prince Ramesuan, and his brother Prince Mahin.
Suriyothai