Narai (Thai: นารายณ) or Ramathibodi III (รามาธิบดีที่ 3) or Ramathibodi Si Sanphet (รามาธิบดีศรีสรรเพชญ) was the king of Ayutthaya from 1656 to 1688 and arguably the most famous Ayutthayan king.
His reign was the most prosperous during the Ayutthaya period and saw the great commercial and diplomatic activities with foreign nations including the Persians and the West. During the later years of his reign, Narai gave his favorite – the Greek adventurer Constantine Phaulkon – so much power that Phaulkon technically became the chancellor of the state. Through the arrangements of Phaulkon, the Siamese kingdom came into close diplomatic relations with the court of Louis XIV and French soldiers and missionaries filled the Siamese aristocracy and defense. The dominance of French officials led to frictions between them and the native mandarins and led to the turbulent revolution of 1688 towards the end of his reign.
Narai’s reign was also known for the 1662–1664 invasion of Burma, the destruction of the briefly independent port city of the Sultanate of Singgora (1605–1680), and the Siam–England war (1687).
The presence of numerous foreigners from the French Jesuits to the Persian delegates has left historians with rich sources of material on the city of Ayutthaya and its conflicts and courtly life in the seventeenth century that otherwise would not have survived the complete destruction of the capital in 1767.