He ruled under the regencies of his mother, Queen Rajendra Rajya Lakshmi Devi (died, 13 July 1785 from tuberculosis), and then of his uncle, Bahadur Shah.

The exigencies of the Sino-Nepalese War in 1788–92 had forced Bahadur Shah to temporarily take a pro-British stance, which led to a commercial treaty with the British in 1792.

[note 1][5][7] By 1797, his relationship with his uncle, who was living a retired life, and who wanted to seek refuge in China on the pretext of meeting the new emperor, had deteriorated to the extent that he ordered his imprisonment (on 19 February 1797) and his subsequent murder (on 23 June 1797).

To make sure that Girvan succeeded to the throne while Kantavati was still alive, Rana Bahadur, aged just 23, abdicated in favor of their son on 23 March 1799, placing his first wife, Raj Rajeshwari, as the regent.

After the inevitable death of Kantavati, Rana Bahadur suffered a mental breakdown during which he lashed out by desecrating temples and cruelly punishing the attendant physicians and astrologers.

A flurry of letters were exchanged between the ex-king and individual courtiers, through which he tried to set them up against Damodar Pande and tried to woo them with promises of lifelong high government positions that could be inherited by their progeny.

[23][24] Back in Kathmandu the court politics turned complicated when Mul Kaji (or chief minister) Kirtiman Singh Basnet, a favorite of the Regent Subarnaprabha, was secretly assassinated on 28 September 1801, by the supporters of Rajarajeshwari.

Bakhatbar Singh Basnet, brother of assassinated Kirtiman Singh, was then given the post of mul kaji[25] During his tenure as the mul kaji, on 28 October 1801, a Treaty of Commerce and Alliance[note 4] was finally signed between Nepal and East India Company that led to the establishment of the first British Resident, Captain William O. Knox, who was reluctantly welcomed by the courtiers in Kathmandu on 16 April 1802.

[note 5][31] The primary objective of Knox's mission was to bring the trade treaty of 1792 into full effect and to establish a "controlling influence" in Nepali politics.

[17][24] After Rajarajeshwari took over the regency, she was pressured by Knox to pay the annual pension of 82,000 rupees to the ex-King as per the obligations of the treaty,[26] which paid off the vast debt that Rana Bahadur Shah had accumulated in Varanasi due to his spendthrift habits.

[35] Such open display of anti-British feelings and humiliation prompted the Governor General of the time Richard Wellesley to recall Knox to India and unilaterally suspend the diplomatic ties.