Thailand: A Buddha statue in Wat Mahathat, Ayutthaya Historical Park, Ayutthaya. Wat Phra Mahathat was built during the reign of Borommaracha I (Boromma Rachathirat I) or Khun Luang Pa Ngua (1370- 1388), who was the third king of the Ayutthaya Kingdom. Ayutthaya (Ayudhya) was a Siamese kingdom that existed from 1351 to 1767. Ayutthaya was friendly towards foreign traders, including the Chinese, Vietnamese (Annamese), Indians, Japanese and Persians, and later the Portuguese, Spanish, Dutch and French, permitting them to set up villages outside the city walls.