evidence: Prithvi Narayan Shah was born 1723 January 7 in Gorkha Darbar. His father’s name is king Narbupal Shah who was the king of Gorkha principality. He enthroned in 1773 April 3. He was very ambitious, farsighted and courageous king. While he enthroned, he decided to expand his territory of principality. Then started to unity the Nepal that was split into variour small principalities. He annexed many principalities to Gorkha (Nepal). After his dearth his successor continued his campaign. His prince Bahadur Shah had given more contributions to unify split Nepal and to comprised many territories of India to Nepal. Teesta in the east, Kankada in the west, and nearby to the confluence of Ganga and Jamuna in the south were annexed by Nepal. India (East India company government) could not bear Nepal spreading out and becoming stronger. So They counter-attacked to Nalapani, Jaithak, and Nakaulanpur and propagated to attack Kathmandu valley. Nepal was weak than India economically. technically, and strategically, so Nepal was compelled to do Sugauli Treaty. Guru Gajaraj Mishra with Chandra Shekhar Upadhyaya for Nepal and parish Bradshow for East India company signed on treaty in 2 December 1815. [...] Most of the experts on International treaty argue that the Sugauli Treaty is not for ever. British had felt that they had done injustice to Nepal by forcing the Sugauli treaty. After the treaty there were territorial disputes immediately. Antu Danda, Illam- 1825, Mechi river 1838, Ramnagar 1840, Tirhut and Sarun were disputed border at that time. As the treaty, boundary demilation is not clear upto now.