The unification of Nepal primarily resulted from the leadership of King Prithvi Narayan Shah, who ruled the Gorkha Kingdom. The mid-18th century was characterized by fragmented principalities scattered across present-day Nepal, including the powerful city-states in the Kathmandu Valley. Prithvi Narayan Shah envisioned a cohesive state that would integrate these regions, enhancing trade and security while resisting foreign influences. He recognized that the fragmentation made the territories vulnerable to external threats, galvanizing him into action.

Starting around 1743, his campaigns commenced with the conquest of neighboring areas, employing a combination of military ingenuity and diplomacy. Prithvi Narayan Shah's forces captured the strategically important city of Kathmandu on this notable date, essentially laying down the foundation for modern Nepal’s territorial integrity. The conquests saw the incorporation of rival territories, each contributing to a larger national narrative.

This military expedience was further bolstered by forging alliances with influential local rulers and navigating the intricate political landscape of the time. The success in capturing Kathmandu not only demonstrated the efficacy of Shah's strategies but also solidified his legitimacy as a unifier. Prithvi Narayan Shah's actions during this period were not merely defensive; they were a calculated maneuver to create a singular Nepali identity amidst regional chaos, ultimately culminating in the establishment of the Shah Dynasty’s rule over a unified Nepal.