History of modern Nepal is said to have begun in 1768 A.D. (1825 B.S.) with Gorkha rulers their successful unification of petty states, the year when Prithvi Narayan Shah, the great King of Nepal, conquered the kingdom of Kathmandu and transferred his capital from Gorkha to Kathmandu. This important even was ended a milestone in this history of modern Nepal. Various small states were merged into a nation. A different ruling dynasty took over the power. The Shah dynasty began to rule and Malla dynasty rule came to an end.

Prithvi Narayan Shah (1742-74): Prithvi Narayan Shah, the maker of modern Nepal. There were number of small kingdoms when Prithvi Narayan Shah became the king of Gorkha. He initiated to expand the territory of the kingdom invading to his neighboring kingdoms like Lamjung, Tanahuhn, Makwanpur, Nuwakot etc. He had brave courageous and expert courtiers, with such a strong army; he was able to defeat Jay Prakash Mall and sat on the throne of Kathmandu on 25 December 1768 (13th Ashwin 1825).

He, soon after that, was able to annex the Patan and Bhaktapur to his kingdom. His son, Bahadur Shah annexed the rest small kingdoms in the east, south, and west during the r rule of Rana Bahadur Shah. Thus the great ruler, Prithvi Narayan Shah changed the entire course of the history of Nepal. With the achievements of this great King, Nepal became a unified, strong and powerful kingdom. Prithvi Narayan Shah was the only king of Nepal who is given the title, " the great". The 27th Paush, the birthday of Prithvi Narayan Shah, is celebrated every year as the National Unification Day".

King Tribhuwan was the eighth Shah king ruler of Nepal. He ascended the throne when he was only five years old on the 20th Feb 1911. There was a family rule of the Ranas during the regime of King Tribhuwan. The Ranas ruled the country as the Prime Minister and the Commander in Chief of the Nepalese Army.