Jang Bahadur and his brothers massacre about 40 members of the Nepalese palace court.

Jung Bahadur Rana,, was born Bir Narsingh Kunwar (1817-1877). His mother, Ganesh Kumari, was the daughter of Kaji Nain Singh Thapa, the brother of Mukhtiyar Bhimsen Thapa from the prominent Thapa dynasty. During his lifetime, Jung Bahadur eliminated factional fighting at court, removed his family's rivals such as the Pandes and Basnyats, introduced innovations in the bureaucracy and judiciary, and made efforts to modernize Nepal. He is considered a significant figure in Nepalese history. Some modern historians blame Jung Bahadur for initiating a dark period in Nepalese history marked by an oppressive dictatorship that lasted 104 years, while others attribute this period to his nephews, the Shumsher Ranas. Rana's rule is often associated with tyranny, debauchery, economic exploitation, and religious persecution.

The Kot massacre took place on 14 September 1846 when then Kaji Jang Bahadur Kunwar and his brothers killed about 30-40 civil officials, military officers and palace guards of the Nepalese palace court including the Prime Minister of Nepal and a relative of the King, Chautariya Fateh Jung Shah along with other senior-most ministers and army generals at the palace armory (Kot) of Hanuman Dhoka in Kathmandu.