The Devahastin or Thephasadin family (Thai: เทพหัสดิน, RTGS: Thephatsadin) is a Thai family of royal descent, tracing its origins from Prince Thepharirak, a nephew of King Rama I.[1] Its best known member was Sanan Devahastin na Ayudhya, better known by his noble title Chaophraya Thammasakmontri, a senior government official of the 1920s–1930s.