Bhimsen was appointed as Hajuriya (personal secretary) of King Rana Bahadur Shah in 1797. Bhimsen went together with Rana Bahadur Shah to Varanasi, India on 1800 after the King was forced by the general people to leave Nepal. In Varanasi, Bhimsen helped the former King Rana Bahadur to prepare for his return to power in 1804. Later, Rana Bahadur dismissed and ordered death penalty to the existing Nepalese mimisters on 1804. He made Bhimsen a "kaji" (equivalent to a minister) of the newly formed government in 1804. Rana Bahadur's murder by his step brother Sher Bahadur in 1806 allowed Bhimsen to kill ninety-three people as criminals. After that, he was given the title of the "mukhtiyar" (equivalent to prime minister).