shiva_linga bro, maithali bahuns are only priest not rulers as said by Rajesh_BP. rulers were like licchavi thakuri after that malla. And only few licchavi were converted into shrestha caste in malla period like raj bamsi, maske not all. the remaining Lichhavis were gradually set aside by the Varman Thakuris and later by the Somvanshi Mallas. Some of the Lichchavis merged with the locals thus intermingling with the Jyapus (old word was 'Bhawo') while others were given social respect (given their heritage) and included within the Srestha (old word was 'Bharo'). present jyapu is combination of gopal kirants and licchavi.here are some link of newar in which it is also metioned that jyapu are gopa kirants and licchavi.

you can go throw this link if you want :