The royal palace at bang pa-in has a history dating back to the 17 century According to a chronicle of Ayutthaya king prasat Thong had a palace constructed on bang pa-in the Chao Pharya River A contemporary Dutch merchant Jeremais van vliet reported that king prasat thong was an illegitimate son of king Ekathosarot who in his youth was shipwrecked on that island and had son with a woman who befriended him the boy grew up to become the chief minister after having usurped the throne he became known as king prasat thong the king founded a monastery wat chumphon nikayaram on the land belonging to his mother on bang pa-in island and then had a pond dug and a palace built to the south of the monastrey the chronicle rocords the name of only one building the aiaswan thiphya-art royal residance which was constructed in 1632 the year of the birth of his son the future king narai