Chettathirat took the reigning name in Ayutthaya as Ramathibodi II.
Invasion of Malacca In 1500, Ramathibodi II dispatched Siamese forces to
subjugate the
Sultanate of Malacca. Although the campaign failed to bring Malacca under Siamese control, Siam succeeded in extracting tribute from the Malacca sultanate as well as from neighboring polities such as
Pattani,
Pahang, and
Kelantan. In 1511, however,
Malacca was conquered by the Portuguese under
Afonso de Albuquerque. A Portuguese embassy led by
Duarte Fernandes reached Ayutthaya in 1518, becoming the first Europeans to make contact with Siam. Ramathibodi II concluded a treaty granting the Portuguese "complete commercial freedom", along with permission to establish Christian missions and construct churches.
War with Lanna In 1513, King Kaew of Lanna launched an invasion into Sukhothai. Ramathibodi II personally led the Siamese forces to repel the Lanna army and subsequently advanced into Lanna territory. In 1515, he sacked
Lampang—a common Southeast Asian practice of punitive raiding without long-term occupation. Afterwards, he appointed his son, Prince
Athittayawong, as King of Sukhothai.
Establishment of the Corvée system In mainland Southeast Asia, political and military strength depended heavily on the control of manpower. In 1518, Ramathibodi II instituted the Siamese
corvée system, which would remain in place until its
abolition by King Chulalongkorn in 1905. Siamese commoners—known as
phrai ()—were subject to lifelong labour duty to the state. All men aged eighteen were registered for conscription, either for military service (
phrai thaan) or for public works (
phrai luang). Although often compared to modern conscription, the Siamese corvée system comprised several distinct categories and obligations. The
Krom Phra Suratsawadi, a department within the royal
bureaucracy, was responsible for overseeing the registration and mobilization of manpower. == Death ==