Borommarachathirat II

Borommarachathirat II ordered the construction of Wat Ratchaburana in Ayutthaya to commemorate his two older brothers who died in a duel for the throne. The temple became a significant religious site and a symbol of royal patronage of Buddhism, featuring a prominent prang and crypt.

Borommarachathirat II led Ayutthayan forces in a successful siege of Angkor, the capital of the Khmer Empire. The city was captured and looted, leading to the Khmer abandonment of Angkor and the relocation of their capital to Phnom Penh. This event marked the decline of the Khmer Empire.

Borommarachathirat II launched a military expedition against the northern kingdom of Lanna, capturing several towns and asserting Ayutthaya's dominance in the region. The campaign resulted in a temporary tributary relationship with Lanna, expanding Ayutthaya's sphere of influence.