Ramathibodi II

Ramathibodi II ordered the construction of Wat Phra Si Sanphet, the holiest temple in the Ayutthaya royal palace complex. The temple housed a large standing Buddha image and served as the site for royal ceremonies. Its construction demonstrated the king's piety and reinforced the link between Buddhism and monarchy.

Ramathibodi II received the first Portuguese diplomatic mission to Ayutthaya, led by Duarte Fernandes. This initial contact established formal relations between the two kingdoms, leading to a treaty in 1516 that allowed Portuguese trade and settlement in Ayutthaya, marking the beginning of European involvement in Siam.

Ramathibodi II signed a treaty with the Portuguese Empire, granting them permission to establish a trading post and reside in Ayutthaya. In exchange, the Portuguese provided firearms and military advisors. This treaty opened Ayutthaya to European trade and introduced Western military technology to the kingdom.

Following the treaty with Portugal, Ramathibodi II incorporated Portuguese-supplied firearms and cannon into the Ayutthayan military. This adoption of gunpowder weapons transformed the kingdom's warfare capabilities, giving Ayutthaya a technological advantage over neighboring states for several decades.