This depiction of Gautama, shown with the double abhaya mudra and dressed in regal attire, was fully developed in Thailand by the 12th century.  The mudra is called “calming the ocean,” which refers to a miracle Gautama performed at Uruvela shortly after his enlightenment.  When floods were threatening the town, he held them back with this mudra, thus converting the local fire-worshipers to Buddhism.

The royal attire is based on a Buddhist scripture found only in Thailand.  It tells the story of Gautama converting the arrogant king Jambupati, by appearing before him dressed as a king and opening a pit containing the fires of hell in front of him.  This narrative replaced the traditional depiction of Gautama wearing plain dress with no adornments which symbolizes his renunciation of worldly ambition.