The name Ayutthaya derives from the Sanskrit word Ayodhyā of the Ramayana epic. Ayodhyā is feminine negation of the word Yodhya which comes from the root Yudh (to fight). A (negation) + Yodhya (winnable) + ā (feminine suffix). So, literally, the name translates as "A city that cannot be fought and won over in a war".

Phra Nakhon Si Ayutthaya, covering 2,556 square kilometres, is on the flat river plain of the Chao Phraya river valley. The presence of the Lop Buri and Pa Sak rivers makes the province a major rice farming area.

Ayutthaya was founded in 1351 by King U-Thong. It was the capital of Thailand (then called Siam) for 417 years from 1351 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 France, during the reign of Louis XIV. His reign was the golden age of trade and culture.

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