Floating krathong along the river was created by Nang Noppamas; the most favorite concubines Sukhothai king. She made krathong as lotus-shaped. The king of Sukhothai floated it along the river. According to Sri Chula Lucks treatise, Phra Ruang (Sukhothai king) said From now on, on the full moon night of the twelfth lunar month, kings of Siam have to make floating lantern- like lotus-shaped- to worship the foot-print of the Buddha on Nammathanati River for ever after.