interference of Sukhothai effectively made it a vassal state of Ayutthaya and it was finally incorporated into the kingdom. Borommatrailokkanat brought about bureaucratic reforms which lasted into the 20th century and created a system of social hierarchy called sakdina, where male commoners were conscripted as corvée labourers for six months a year. Ayutthaya was interested in the Malay peninsula, but failed to conquer the Malacca Sultanate which was supported by the Chinese Ming dynasty. European contact and trade started in the early-16th century, with the envoy of Portuguese duke Afonso de Albuquerque in 1511. Portugal became an ally and ceded some soldiers to King Rama Thibodi II. The Portuguese were followed in the 17th century by the French, Dutch, and English. Rivalry for supremacy over Chiang Mai and the Mon people pitted Ayutthaya against the Burmese Kingdom. Several wars with its ruling Taungoo dynasty starting in the 1540s in the reign of Tabinshwehti and Bayinnaung were ultimately ended with the capture of the capital in 1570. Then was a brief period of vassalage to Burma until Naresuan proclaimed independence in 1584. Ayutthaya then sought to improve relations with European powers for many successive reigns. The kingdom especially prospered during cosmopolitan Narai's reign (1656–1688) when some European travelers regarded Ayutthaya as an Asian great power, alongside China and India. However, growing French influence later in his reign was met with nationalist sentiment and led eventually to the Siamese revolution of 1688. However, overall relations remained stable, with French missionaries still active in preaching Christianity. After a bloody period of dynastic struggle, Ayutthaya entered into what has been called the Siamese "golden age", a relatively peaceful episode in the second quarter of the 18th century when art, literature, and learning flourished. There were seldom foreign wars, apart from conflict with the Nguyễn Lords for control of Cambodia starting around 1715. The last fifty years of the kingdom witnessed bloody succession crises, where there were purges of court officials and able generals for many consecutive reigns. In 1765, a combined 40,000-strong force of Burmese armies invaded it from the north and west. The Burmese under the new Alaungpaya dynasty quickly rose to become a new local power by 1759. After a 14-month siege, the capital city's walls fell and the city was burned in April 1767. Thonburi Kingdom The capital and many of its territories lay in chaos after the war. The former