Once upon a time in the remote past when the king of these parts was defeated by the forces of an invader, the women of the royal palace, rather than fall into the hands of foe, fled into the jungles with the Saises and Chamars belonging to the palace. From these sprang the Tharus.
R.H. Neville, 1904.
This is the real story of the Tharu: "…four sons and five daughters of King Okamukha of Banares left the kingdom in a huff and moved to Kapil's Ashram. Kapil allowed them to clear the land and settle there on the condition that the new state be named after him, 'Kapilvastu' . The Tharu are their descendants and have spread over the entire length of the Tarai."
Ramanand Prasad Singh, 1982.