Analysis of information sources in references of the Wikipedia article "Ayutiya krallığı" in Azerbaijani language version.
The spot on which the present capital stands, and the country in its vicinity, on both banks of the river for a considerable distance, were formerly, before the removal of the court to its present situation called Bang-kok; but since that time, and for nearly sixty years past, it has been named Sia yuthia, (pronounced See-ah you-tè-ah, and by the natives, Krung, that is, the capital;) it is called by both names here, but never Bang-kok; and they always correct foreigners when the latter make this mistake. The villages which occupy the right hand of the river, opposite to the capital, pass under the general name of Bang-kok.
There is an old city ... called by the people Müang U Thong (the city of King U Thong) and there is a tradition that Thao U Thong reigned over this city until an epidemic broke out and the people died in great numbers. He then abandoned the city and turning to the East looked out for another place to establish the capital; but the epidemic did not abate. He then crossed the Suphan (Tachin) river to escape the ravages of the epidemic, and even at the present time near the Suphan river there is a place called "Tha Thao U Thong" 'i. e.' the crossing of King U Thong.
There is an old city ... called by the people Müang U Thong (the city of King U Thong) and there is a tradition that Thao U Thong reigned over this city until an epidemic broke out and the people died in great numbers. He then abandoned the city and turning to the East looked out for another place to establish the capital; but the epidemic did not abate. He then crossed the Suphan (Tachin) river to escape the ravages of the epidemic, and even at the present time near the Suphan river there is a place called "Tha Thao U Thong" 'i. e.' the crossing of King U Thong.
The spot on which the present capital stands, and the country in its vicinity, on both banks of the river for a considerable distance, were formerly, before the removal of the court to its present situation called Bang-kok; but since that time, and for nearly sixty years past, it has been named Sia yuthia, (pronounced See-ah you-tè-ah, and by the natives, Krung, that is, the capital;) it is called by both names here, but never Bang-kok; and they always correct foreigners when the latter make this mistake. The villages which occupy the right hand of the river, opposite to the capital, pass under the general name of Bang-kok.