Factionalism inside the royal family led to a period of instability . In 1846 , a plot was discovered revealing that the reigning queen had planned to overthrow Jung Bahadur Kunwar , a fast-rising military leader . This led to the Kot massacre ; armed clashes between military personnel and administrators loyal to the queen led to the execution of several hundred princes and chieftains around the country . Jung Bahadur Kunwar emerged victorious and founded the Rana dynasty , later known as Jung Bahadur Rana . The king was made a titular figure , and the post of Prime Minister was made powerful and hereditary . The Ranas were staunchly pro-British and assisted them during the Indian Rebellion of 1857 ( and later in both World Wars ) . Some parts of the Terai region populated with non-Nepali peoples were gifted to Nepal by the British as a friendly gesture because of her military help to sustain British control in India during the rebellion . In 1923 , the United Kingdom and Nepal formally signed an agreement of friendship that superseded the Sugauli Treaty of 1816
Kot massacre
Kot massacre
Nepal