Ayutthaya was founded in 1350 by King U-Thong. It was the capital of Thailand (then called Siam) for 417 years from 1350 until it was sacked by the Burmese army in 1767. During this era, now usually referred as the Ayutthaya period or Ayutthaya kingdom, Ayutthaya was ruled by 33 kings of 5 different dynasties. The Kingdom became a major regional player, and a trade center of the East, a meeting point of European merchants and Asian traders. Notable monarchs during the Ayutthaya period include King Naresuan the Great, who liberated Ayutthaya from the first Burmese occupation and embarked on a reign of conquest, and King Narai the Great, who initiated diplomatic relations with the France, during the reign of Louis XIV. His reign was the golden age of trade and culture.
The city was positioned in a strategic position. During several months of the year, the flood plains around the cities would be flooded by the many rivers around the city. Enemy sieges were thus impossible, and forced to withdraw. This advantage was a contributing factor in the many failed Burmese invasions.