The king is the avatar (อวตาร) of Shiva (ศิวะ) or Vishnu (วิษณุ) - Lord of the universe
Thai king was the protector of the people.
Thai king became the Lord of the Land or who Rules the Earth (Phra Chao Phaedin พระเจ้าแผ่นดิน)
The coronation ceremony was performed by brahmins (พรามหณ์)