Divison of Nepal into three Kingdoms:

 During 1482, Nepal was split into three kingdoms by the sons of Yakshamalla, with centers of power at Kathmandu, Patan and Bhadgaon (also known as Bhaktapur). Each of these states controlled territory in the surrounding hill areas, with particular importance attached to the trade routes northward to Tibet and southward to India that were vital to the valley's economy. There were also numerous small principalities in the western and eastern hill areas, whose independence was sustained through a delicate balance of power based upon traditional interrelationships and, in some cases, common ancestral origins (or claims thereto) among the ruling families.
       

By the 16th century virtually all these principalities were ruled by dynasties claiming high-caste Indian origin whose members had fled to the hills in the wake of Muslim invasions of northern India. This state of affairs lasted until the 18th century when the influence of political change and expansion within Nepal’s large and powerful neighbors of India and China began to be felt.